September 2025
 

The Logic of Strategic Substitution

Under the Nuclear Shadow
By Fiona Cunningham
Princeton University Press, 2025

Reviewed by Elsa B. Kania 

Under the Nuclear Shadow is a critical contribution to understanding the rationales informing China’s military force posture and evolving approach to deterrence. Author Fiona Cunningham introduces a theory of strategic substitution and uses it to examine the logic behind China’s drive to develop information-age capabilities. As the Chinese People’s Liberation Army (PLA) faces the limited war dilemma of defining the challenge of achieving objectives through military force while mitigating risks of nuclear conflict, its pursuit of coercive leverage has motivated significant investments and transformation of its force posture. In particular, Chinese leaders and military strategists have regarded the development of information-age capabilities, especially in advancing cyberspace operations, counterspace weaponry, and precision conventional missiles, as uniquely advantageous, given their greater flexibility and potential for improved credibility. The strategic rationales and historical perspectives that this book provides are invaluable to our understanding of the contours of Chinese military power.

China’s Search for Leverage

The book traces the trajectory of China’s military modernization and examines several critical inflection points in which “leverage deficits” provided an impetus for Chinese leaders to prioritize pursuing certain information-age capabilities. In particular, the 1995-1996 Taiwan Strait crisis, when the U.S. military deployed aircraft carriers off the coast of Taiwan in response to China’s attempted coercion, and the 1999 Belgrade embassy bombing, which Beijing believed to be deliberate, can be regarded in retrospect as moments when Chinese leaders became acutely aware of shortfalls in their capabilities relative to the United States. These realizations created catalytic impacts driving Beijing’s decision to develop capabilities that Washington, regarded as a powerful potential adversary, could fear. While Cunningham characterizes these moments primarily as political crises, the military motivations and considerations are closely entwined, especially after factoring in the singular demonstrations of U.S. military capability in each instance.

The theory of strategic substitution is presented as a puzzle and a unique choice by China to pursue an alternative approach relative to adopting a nuclear-first-use posture (brinksmanship) or to develop superior conventional capabilities. By contrast, China decided to bet on information-age capabilities, here defined as cyberspace, counterspace, and conventional precision missile capabilities. This approach could be regarded as highly risky yet pragmatic; Chinese leaders were willing to bet on new domains and more untested technologies, yet also regarded these specific capabilities as quicker, feasible options for accelerated development relative to more conventional alternatives.¹

This book provides a deeply researched and authoritative accounting of how each of these elements of force posture evolved. Relative to nuclear weapons, which Chinese leader Mao Zedong once dismissed as “paper tigers,” given the perceived limitations of the credibility of nuclear threats, precision strike, counterspace, and cyberspace capabilities are regarded as more usable, flexible, and credible. As such, these capabilities can provide the “coercive leverage” that China seeks, while allowing for tight control of the risks of escalation. Cunningham defines the posture that follows from this capability development as one of “calibrated escalation” that provides a range of options along a ladder up to but still “under the nuclear shadow.”

Ultimately, these capabilities, which might be characterized as a new triad complementing the fully nuclear triad that China has been developing in parallel, can be regarded as instruments of an overall system of strategic deterrence that is extending increasingly beyond China’s nuclear arsenal to incorporate new concepts of information deterrence, as well as cyber and space deterrence. Pursuant to the increased importance of new domains and emerging capabilities, from artificial intelligence to deep sea developments, the factors that may influence deterrence are increasingly complex and multifaceted.

While Cunningham looks back to the 1990s for moments with catalytic impacts on China’s force posture, more recent noteworthy events may be relevant in anticipating future developments. The reported misperceptions among Chinese leaders that caused Chairman of the Joint Chiefs of Staff Gen. Mark Milley to engage his counterpart in the PLA Joint Staff Department in October 2020 and January 2021 in an effort to provide assurance that there was no U.S. intention to attack China may be regarded as another episode with potential catalytic impacts that illustrates the recent mistrust in China-U.S. relations.² The PLA’s response to House Speaker Nancy Pelosi’s visit to Taiwan in August 2022 also may have proven a moment that demonstrated a proof of concept for applying military power in a retaliatory manner and for the exercise of pressure, a trend that has become more prominent in the years since then.

This force posture and strategic outlook possess certain limitations. For China, the use of such information-age capabilities in signaling for coercive or deterrent purposes is inherently challenging. Among the mechanisms that Chinese military strategists anticipate using are deliberate disclosures, as by testing and demonstrations that publicly showcase such capabilities. The risks of entanglement in the underlying command systems and the dependencies between these domains create complexities, which may complicate the carefully modulated approach to escalation that Chinese leaders envision enacting. In particular, the increasing nuclear-conventional entanglement that has become a troubling feature of China’s overall posture has raised concerns about risks of escalation.³

Beijing’s capacity to convey the intentions behind certain activities and to influence potential adversaries’ perceptions of these capabilities constitutes another difficulty where there is significant potential for misperception. For instance, although the book mentions Volt Typhoon in passing, this is an episode that merits more detailed examination and consideration as an illustration of China’s approach. In particular, the reported pre-positioning of malware in U.S. and allied critical systems and infrastructure appears to highlight the realization operationally of certain concepts that Chinese military writers had long discussed conceptually.⁴ Such peacetime operations are also consistent with a view of the cyber domain that regards a blurring of boundaries between peace and warfare, as well as the inherent interrelatedness of reconnaissance and offensive operations, as features of this new domain of conflict.

In that particular episode, even more curious was the apparent acknowledgment by Chinese officials of responsibility for these attacks and their statements to reportedly surprised U.S. counterparts that the purpose behind this operation was to respond to U.S. support and assistance for Taiwan.⁵ Unspecified in public reporting is whether that activity should be regarded as a punitive, coercive, or deterrent measure. Absent such explicit conveying of intentions, the intent behind cyber operations can be easily misconstrued; when the boundary between preparation for and imminent conduct of offensive operation is inherently uncertain from a technical perspective, presence on sensitive systems and networks, especially in a moment of crisis, could be taken as an indication of aggressive intentions, rather than a deterrent measure.

Questions of Command

Among the notable avenues for future inquiry is how China’s approach to command and control influences its capacity to leverage these information-age capabilities. Cunningham traces the evolution of PLA command of cyberspace capabilities from an earlier more freewheeling environment to increasingly centralized control, which prompted creation of the Strategic Support Force and later the PLA Cyberspace Force. The inherent question is whether Chinese leaders can achieve the desired strategic effects while limiting the delegation of control over strategic capabilities when the Chinese Communist Party prefers to maintain more centralized control.

To date, China’s capacity for coordination appears limited. Cunningham notes that there is little evidence of a structure to coordinate actions associated with strategic deterrence. Although there is almost certain to remain a high degree of opacity associated with these processes, the Central Military Commission’s Joint Operations Command Center presents a feasible mechanism for such coordination. The reported construction of a new potential wartime command center in Beijing, seemingly buried deep enough underground to withstand a nuclear attack, highlights the apparent intensity of concerns driving these developments.⁶ Meanwhile, Chinese political leaders may recognize the necessity of more delegated mechanisms of command in certain domains and for certain missions that place greater premium on the exercise of initiative.

The Nuclear Posture Puzzle

Among the inherent challenges associated with such a book is the dynamism of the topic. Under the Nuclear Shadow has been published against the backdrop of an active debate on the dramatic expansion of China’s nuclear arsenal. At first glance, the extent of China’s investment in modernizing, diversifying, and expanding its nuclear forces—which the U.S. Defense Department’s 2024 “China Military Power” report predicts will probably continue over the next decade⁷—would appear to contradict some of the premises in Under the Nuclear Shadow. Cunningham concentrates on the drivers for China’s development of non-nuclear strategic capabilities to substitute for nuclear threats. Yet the logic underlying these developments parallels that of strategic substitution, insofar as the PLA’s pursuit of more diversified nuclear capabilities allows greater optionality.

In this regard, the trend overall has been to expand options within and along the nuclear section of the escalation ladder. This drive for nuclear overmatch and escalation dominance appears to reflect a juxtaposition of a degree of insecurity, including in the context of U.S. missile defense capabilities, and the extent of China’s military ambitions, with the drive to become a world-class military by mid century.

To some extent, there may be certain tensions or tradeoffs from a resourcing perspective between the logics of strategic substitution and the pursuit of nuclear overmatch. In parallel, there are indications that the PLA is increasing the readiness of its nuclear forces with a focus on rapid response, which shifts closer to a launch on warning posture. While there are reasons to hope that an approach of calibrated escalation, such as Cunningham characterizes China’s approach, will prevail, grounds for concern also arise about the apparent confidence of Chinese leadership that escalation can be controlled, especially given the potential for mistakes in signaling or misperception.

Author’s Contributions

Overall, Cunningham’s research provides important theoretical contributions to understanding Chinese military power. Her characterization of China’s force posture as one of calibrated escalation also possesses utility and value in projecting how Beijing might employ these capabilities for coercion in conflict. The theoretical framework of strategic substitution accounts for the logic of China’s bets on information-age capabilities as an attempt to offset U.S. military advantages.⁸ This drive for leverage centered on achieving quick, credible capabilities within a shorter time for the three elements of force posture is worth noting. However, in parallel, Chinese military modernization has pursued capabilities with longer timelines for development.

Perhaps the most fundamental consideration raised by this book is how to project the future trajectory of Chinese military power. The author articulates three plausible scenarios for China’s force posture: continuation of strategic substitution, change to a nuclear-first-use posture, or pursuit of conventional victory. These options appear far from mutually exclusive. At present, China appears to be pursuing a combination of the three trajectories, as reflected in continued development of information-age capabilities juxtaposed with dramatic expansion of its nuclear posture—albeit without a clear change to its position on nuclear first use—and significant expansion of conventional capabilities. If Chinese leaders start to face resource constraints because of economic headwinds, the telling sign may be how resources are prioritized and allocated among these different categories of capabilities.

This framework of strategic substitution provides a useful approach that has potential applicability to both nuclear and non-nuclear states. At a time when U.S. security guarantees and extended deterrence commitments are starting to be called into question, there are rationales for some U.S. allies and partners to pursue more sources of leverage and independent capabilities. For instance, Taiwan is pursuing new asymmetric capabilities through foreign military sales and domestic procurement, such as precision strike missiles, including coastal defense cruise missiles, and a growing number of unmanned systems.⁹ Relative to when China initially embarked on a quest to develop information-age capabilities, its tendency today toward commercial developments may make these strategies and the development of comparable capabilities more accessible to a greater range of states.

Ultimately, this work raises critical questions as the Chinese military looks to the future of power and warfare. Implicit in the theory of strategic substitution is how Chinese political and military leaders make decisions about the bets they place on technologies under conditions of uncertainty. To no small extent, China’s pursuit of information capabilities also occurred against the backdrop of concepts of a revolution in military affairs, the notion of a dramatic transformation that centers on the decisive impacts of information in warfare. These ideational influences have shaped decision-making on which technologies to pursue and prioritize.

Among the potential avenues for future research are how China’s drive for military innovation, which is producing new, yet untested capabilities, might be integrated into its overall force posture. Beyond the information-age capabilities that Cunningham characterizes as critical to deterrence, Chinese military strategists also are starting to explore the impacts of unmanned systems, military applications of artificial intelligence, and biotechnology developments, along with other emerging technologies, as new frontiers of military struggle and confrontation that could reshape future deterrence.¹⁰ In particular, the development of unmanned systems and artificial intelligence promise new near-term pathways for coercive leverage, and unmanned systems, particularly, are already starting to be applied in pressure operations targeting U.S. and Taiwanese decision-making. In this regard, these trends and themes will likely remain the subject of active debate with significant implications for the Indo-Pacific region and the global military balance.

ENDNOTES

1. There is also the question of how strategic substitution as a concept relates to other concepts prominent in Chinese writings, such as the notion of “asymmetrically counterbalancing” (非寇聳制衡) powerful adversaries that the Science of Strategy highlights. These information-age and other disruptive capabilities can also be characterized as shashoujian (杀手恝), or “assassin’s mace” capabilities in more popular parlance.

2. Phil Stewart and Patricia Zengerle, “Under fierce Republican attack, U.S. General Milley defends calls with China,” Reuters, September 28, 2021.

3. David C. Logan, “Are They Reading Schelling in Beijing? The Dimensions, Drivers, and Risks of Nuclear-Conventional Entanglement in China.” Journal of Strategic Studies 46, no. 1 (2023): p. 5-55. Henrik Stålhane Hiim, M. Taylor Fravel, and Magnus Langset Trøan. “The Dynamics of an Entangled Security Dilemma: China’s Changing Nuclear Posture.” International Security 47, no. 4 (2023): 
p. 147-187.

4. See the initial reporting from Microsoft threat researchers on this activity, among other public sources: https://www.microsoft.com/en-us/security/blog/2023/05/24/volt-typhoon-targets-us-critical-infrastructure-with-living-off-the-land-techniques/

5. Dustin Volz, “In Secret Meeting, China Acknowledged Role in U.S. Infrastructure Hacks,” Wall Street Journal, April 10, 2025.

6. Demetri Sevastopulo, Joe Leahy, Ryan McMorrow, Kathrin Hille, and Chris Cook, “China builds huge new wartime military command centre in Beijing,” Financial Times, January 30, 2025.

7. For further context, see :U.S. Department of Defense, “Military and Security Developments Involving the People’s Republic of China,” December 2024.

8. Looking at the vernacular of U.S. defense debates, the question can also arise as to whether characterizing China’s approach to force development as an “offset strategy” would be appropriate. See, for instance: Timothy Walton, “Securing the Third Offset Strategy,” Joint Force Quarterly 82 (2016): p. 6-15.

9. See for instance: Justin Ling, “Taiwan Is Rushing to Make Its Own Drones Before It’s Too Late,” Wired, June 23, 2025.

10. See the PLA National Defense University’s 2020 edition of Science of Military Strategy (战略学) for further context.

September 2025
By Kelsey Davenport

France, Germany, and the United Kingdom notified the UN Security Council of their intention to restore sanctions on Iran that were modified as part of the 2015 nuclear deal. The move came after the three countries and Iran failed to reach an agreement on extending the mechanism for restoring the sanctions, which is set to expire in October, in exchange for Iran taking steps to increase transparency over its nuclear program.

In an Aug. 28 statement, the Europeans said that Iran’s violations of the nuclear deal, formally known as the Joint Comprehensive Plan of Action, are “clear and deliberate” and they raised concerns about “sites of major proliferation concern” in Iran that are no longer being monitored. According to UN Security Council Resolution 2231, which endorsed the nuclear deal and laid out the mechanism for restoring the UN sanctions on Iran using a process that cannot be blocked, the UN sanctions will be reimposed after 30 days if the Security Council does not pass a new resolution continuing sanctions relief.

The Europeans, however, said they will “use the 30-day period to continue to engage with Iran” on an agreement to extend the snapback deadline, which is set to expire in October.

Iranian Foreign Minister Abbas Araghchi said the move to restore the UN sanctions was “unjustified” and that Iran will respond appropriately to “protect its interests.”

European and Iranian diplomats met Aug. 25 in Geneva but the session ended without an agreement on the steps Iran could take in exchange for the Europeans extending the snapback mechanism.

According to the Aug. 28 statement, the Europeans are willing to extend the snapback mechanism if Iran takes steps to resume negotiations, comply with its safeguards obligations, and “address our concerns regarding the highly enriched uranium stockpile.”

Iran announced that it would allow the International Atomic Energy Agency (IAEA) to resume inspections at certain nuclear facilities, but that did not appear to be enough to persuade the Europeans, known as the E3, who also want to see talks resume between the United States and Iran.

Iran is legally required to implement a safeguards agreement. but following the illegal Israeli and U.S. attacks on its nuclear facilities in June, Tehran prohibited cooperation with the IAEA. Iran only announced on Aug. 26 that agency inspectors were back in Iran and had been permitted to access Bushehr, the country’s operating nuclear power plant. It is unclear if or when Iran will allow inspectors to return to other facilities, including those damaged by the Israeli and U.S. attacks.

Araghchi suggested on Aug. 28 that a sanctions snapback could reverse progress on cooperation with the agency.

Ahead of the European-Iranian meeting in Geneva, Iranian Supreme Leader Ayatollah Ali Khamenei said that the nuclear issue is “unsolvable” and suggested that Iran is not ready to conduct direct negotiations with the United States over its nuclear program. Iran will not be “obedient” to the United States, he said in an Aug. 24 speech.

U.S. Secretary of State Marco Rubio welcomed the European decision to trigger snapback and said that Washington “remains available for direct engagement” with Tehran. Snapback “enhances” U.S. readiness for diplomacy, he said.

The European move does not come as a surprise. The Europeans have said for weeks that they would reimpose sanctions lifted by the Security Council resolution that endorsed the 2015 nuclear deal if there is no progress in resuming negotiations and IAEA inspections by the end of August.

In addition to Iran allowing the IAEA back into its nuclear sites and restarting talks, the Europeans appear to be looking for Iran to take steps to account for its stockpile of 60-percent enriched uranium-235.

The stockpile of 60-percent U-235 is particularly concerning because it can be quickly enriched further to weapons-grade levels. Iran said it moved the stockpile after initial Israeli military strikes June 13; U.S. officials have said it is unclear where all of that material is currently located.

Iran has threatened to withdraw from the Nuclear Nonproliferation Treaty if the UN sanctions are reimposed. Manouchehr Mottaki, a member of Iran’s parliament, said that body has a “finger on the trigger” and needs “only 24 hours” to approve steps to withdraw from the treaty. Iran has the legal right to withdraw from the NPT. To do so, Tehran would need to send a letter to the Security Council outlining the “extraordinary events” that have “jeopardized the supreme interests of its country.” Withdrawal is completed three months after that step.

If snapback were extended, it could buy time for Iran and the United States to return to negotiations. It is not clear, however, that a short extension would be sufficient.

Araghchi told Iranian state-run media Aug. 20 that the time for “effective negotiations” with the United States has not yet arrived. Statements by Iranian and U.S. officials suggest that the two sides have hardened their positions on enrichment since the June strikes by Israel and the United States, with Iran demanding that any deal recognize the country’s enrichment program and the United States saying that Iran must give up enrichment. (See ACT, June 2025.)

Iran does not appear to be enriching uranium currently due to the damage to its enrichment facilities at Natanz and Fordow, but it has the capacity and the materials necessary to resume enrichment.

Furthermore, uncertainties over the status and location of Iran’s nuclear materials will likely create new challenges in verifying any future deal, particularly if Iran continues to refuse to allow the IAEA access to its nuclear sites.

Russia and China have expressed opposition to snapping back sanctions on Iran.

Russia drafted a resolution calling for an extension to the snapback mechanism at the Security Council. The draft, dated Aug. 25, recognized the “necessity of allowing additional time for negotiations” and called for a six-month extension to the snapback mechanism. The draft urges all participants who negotiated the 2015 nuclear deal, which Trump abandoned in 2018, to “immediately resume negotiations.”

The draft makes no reference to Iran’s implementing safeguards.

September 2025
By Xiaodon Liang

President Donald Trump signaled that the United States is preparing to resume discussions on nuclear arms control with Russia and said that the topic was raised during an Aug. 15 summit with Russian President Vladimir Putin.

“We have restrictions [on nuclear weapons] and they have restrictions. That’s not an agreement you want expiring,” Trump said July 25 in response to questions from the Russian newswire TASS regarding the February 2026 expiration of the New Strategic Arms Reduction Treaty.

“We are starting to work on that,” he said.

En route to Anchorage, Alaska, for the summit, Trump told Fox News that, “we have nuclear treaties to discuss. We have a lot of things to discuss that normally would be something that would come naturally. But it’s not so natural now because of Ukraine.”

He elaborated slightly Aug. 25, telling reporters at the White House that he wants a nuclear deal that includes China as well as Russia and “talked about that also” with Putin in Alaska. But such negotiations can be put off until the Russian war on Ukraine is “over with,” Trump said according to Reuters.

Speaking at the Kremlin Aug. 14, Putin likewise said Russia aimed “to establish long-term conditions for peace not only between [the United States and Russia] but also in Europe and indeed globally—especially if we proceed to subsequent stages involving agreements on strategic offensive arms control.”

Trump had invited Putin to Alaska for a bilateral meeting to advance negotiations on a ceasefire in Ukraine. The summit ended without an agreement, but the sides indicated a willingness to continue talks based on tentative understandings reached during a meeting between the heads of state and two senior advisors on each side. A scheduled lunch between larger delegations was canceled.

The meeting was dominated by continuing disagreements over how to end the full-scale Russian invasion of Ukraine. Although Putin said at a joint press conference following the talks that the two presidents had reached an “understanding” and that the dialogue had yielded “emerging progress,” Trump was quick to deny that any agreement was close.

According to reporting by The New York Times, citing unnamed European security officials, Putin had pressed Trump to advocate for a peace deal whereby Ukraine would acknowledge the cession of two regions to Russia—Donetsk and Luhansk—and withdraw from territories within those regions it still controlled.

Putin was successful in at least convincing Trump to drop an approach, previously agreed with European allies days before the summit, to negotiate for a ceasefire first before seeking a full peace agreement. In an Aug. 16 social media post, Trump indicated that he would prefer, “to go directly to a Peace Agreement, which would end the war, and not a mere Ceasefire Agreement, which often times do[es] not hold up.”

But Trump did indicate for the first time, in an Aug. 16 call with Ukrainian President Volodymyr Zelenskyy, the U.S. willingness to provide Ukraine with security guarantees as part of a postwar settlement.

Zelenskyy and a group of European allies discussed the exact form of those guarantees, as well as the peace negotiations in general, with Trump during an Aug. 18 meeting in Washington. According to a press release the next day from the office of UK Prime Minister Keir Starmer, European military officials will meet with U.S. counterparts to formulate a plan to “deliver robust security guarantees and prepare for the deployment of a reassurance force” after the war ends. Ukraine will also purchase $90 billion in U.S. arms as part of efforts to provide for its own security, Zelenskyy said at a briefing in Washington.

Although Trump was quick to rule out the deployment of U.S. troops in Ukraine in an Aug. 19 interview with Fox News, he suggested instead that the United States might provide air support as part of its guarantees.

But even as supporters of Ukraine come closer to defining a viable security guarantee, Russia has reiterated its opposition to any external military presence in Ukraine. In an Aug. 18 statement, Russian Foreign Ministry Spokesperson Maria Zakharova said Russia “unequivocally reject[s] any scenarios involving the deployment of NATO military contingents in Ukraine.” 

September 2025
By Xiaodon Liang

The Pentagon’s Golden Dome office expects to develop within 60 days an “objective architecture” to flesh out its concept of the missile defense shield, a signature strategic initiative of U.S. President Donald Trump, a top official said.

Space Force Gen. Michael Guetlein, the direct reporting program manager for Golden Dome, said he was responsible for completing the study by late September 2025, after which it will be briefed to the deputy secretary of the Air Force.

Guetlein, who made the comments at a Space Foundation event July 22, was confirmed July 17 to his new position by the U.S. Senate. According to Guetlein, his position—informally known as the Golden Dome “czar”—comes with a “whole list of authorities” delegated by the secretary of defense.

Speaking on a controversial component of the Golden Dome program, a proposed space-based interceptor constellation, Guetlein claimed, “that technology exists. I believe we have proven every element of the physics that we can make it work.”

“What we have not proven is: first, can I do it economically; and then second, can I do it at scale? Can I build enough satellites to get after the threat? Can I expand the industrial base fast enough to build those satellites?” he asked.

Guetlein’s acknowledgement of the economic challenges confronting a space-based interceptor constellation mirrors the concerns expressed in a Congressional Budget Office study of potential costs published May 5. The study estimated that a constellation sized to defend against a small number of intercontinental ballistic missiles (ICBMs) fired by North Korea would cost between $161 billion and $542 billion over 20 years. (See ACT, June 2025.)

The Golden Dome, in contrast, is supposed to be able to defend the United States against peer attacks, meaning China and Russia, Trump specified in his January executive order initiating the program.

Although Guetlein’s office has been tasked with detailing the specific architecture for the Golden Dome, the president already approved a conceptual plan in May. According to leaked presentations from an industry conference in early August, the plan envisions four integrated layers of missile interceptors, one in space and three on land.

The existing Ground-based Midcourse Defense (GMD) system, originally designed to defend the homeland against limited rogue-state ICBM attacks, should be expanded to include a new silo field in the Midwestern continental United States, Reuters reported, citing the newswire’s analysis of the leaked presentation. The existing GMD system, currently based in Alaska and California, is set to be upgraded with a Next Generation Interceptor beginning in 2030, a year and a half behind schedule, according to contractor Lockheed Martin’s latest timeline estimates.

Congress voted earlier this year in its annual defense policy bill to require the Pentagon to deploy a third GMD site with the upgraded interceptor on the East Coast by 2031.

The conference presentation also indicated a role for a land-based variant of the Aegis ship-based ballistic missile defense system, the Terminal High Altitude Area Defense system, and the localized short-range Patriot air and missile defense system.

Networking these interceptors, as well as new and existing sensors, will be a critical challenge for the program. “Our first near term focus is going to be on integration of command and control of the various assets that have been built across all those stovepipes” between services and programs, Guetlein said.

The general also addressed concerns regarding oversight of spending on Golden Dome. The Senate Armed Services Committee is proposing, in its draft of this year’s defense authorization act, that Congress require annual briefings by the secretary of defense on the Golden Dome’s progress and costs.

Because key components of the program—including space-based interceptors—will be paid for by a special multiyear reconciliation appropriation passed by Congress earlier this summer, the Defense Department has not provided budget justification documents for those programs akin to those provided to Congress for regular annual requests.

“With that comes an enormous amount of responsibility by the [department] to execute those funds with discipline, but also with transparency,” Guetlein said.

September 2025
By Kelsey Davenport

South Korea’s new president outlined a three-step process for achieving the denuclearization of the Korean peninsula that would start with a freeze on North Korea’s nuclear weapons program, but Pyongyang does not appear interested in engaging with Seoul.

In an interview with Japanese newspaper Yomiuri Shimbun published Aug. 21, President Lee Jae-myung said that “simply clamoring” about denuclearization will not achieve that objective and that it is time to “actively engage” North Korea in dialogue.

To achieve denuclearization, Lee outlined a three-step process. He described a freeze in the North Korean nuclear and missile programs as the first step toward denuclearization. The second step would be to “scale” down North Korea’s current arsenal, he said, followed by the third step, which would be “complete denuclearization.” He also said that North and South Korea could mutually prosper if the two countries “recognize and respect” each other. He suggested that South Korea, Japan, and the United States should all be involved in diplomacy with North Korea.

Lee, who was elected in June, called during his campaign for de-escalating tensions with North Korea and restoring a 2018 military cooperation agreement that his predecessor abandoned as part of a more confrontational approach to North Korean provocations. Soon after taking office, Lee ordered South Korea to remove loudspeakers from the border that the previous administration used to broadcast criticisms of the North Korean regime.

Lee also appeared to acknowledge that South Korea’s approach to North Korea would account for Pyongyang’s decision to no longer seek reunification of the Korean peninsula as a long-term policy objective.

In an Aug. 15 speech, he said that South Korea must respect North Korea’s political system and said that Seoul does not seek “unification by absorption.”

Thus far, North Korea has rejected Lee’s call for rebuilding trust and engaging in dialogue.

In an Aug. 20 commentary in the state-run Korean Central News Agency, Kim Yo Jong, the sister of the country’s leader, Kim Jong Un, said that Lee continues to “tediously talk about peace and improved relations, being well aware that it is impossible to realize them.”

She said that Seoul “cannot be a diplomatic partner” for North Korea because it is “not serious, weighty, or honest” and belittled Lee.

Although Kim’s comments rejected dialogue with South Korea, she appeared to keep open the option for negotiations with the United States under the right conditions.

In July 28 remarks, Kim said that relations between U.S. President Donald Trump and her brother are “not bad” but that there will be no talks between the two countries if the U.S. goal is the dismantlement of North Korea’s nuclear weapons program. North Korea’s nuclear status is “irreversible,” she said, and the United States must recognize this status as a “prerequisite” for any future engagement.

Kim Jong Un also reiterated the country’s nuclear status during a July 29 session of North Korea’s Supreme People’s Assembly.

He said that “as long as nuclear weapons exist,” North Korea’s steps toward “strengthening nuclear power won’t stop.” North Korea will never declare its intention to denuclearize to “meet the other side’s conditions” for engagement, he said.

He made a similar comment Aug. 20 in response to U.S.-South Korean combined, joint military exercises. The exercises, which began Aug. 18, are focused on “strengthening the alliance’s response capabilities,” according to an Aug. 8 U.S. Army press release.

Kim said the military drills are a clear indication that the two countries are pursuing a “hostile and confrontational” approach to North Korea. He said that North Korea must “rapidly expand” its nuclear weapons program in response.

Although the Trump administration has said little about the details of its North Korea policy, U.S. officials have reiterated that Washington is focused on denuclearization. The White House told Fox News July 31 that Trump is open to meeting Kim again, but his objective remains the denuclearization of the Korean peninsula, a point Trump and Kim agreed to during their June 2018 summit meeting. (See ACT, July/August 2018.)

After U.S. Secretary of State Marco Rubio met with South Korean Foreign Minister Cho Hyun Aug. 14, the two officials reaffirmed the goal of “complete denuclearization” of North Korea and the importance of enforcing sanctions on the country.

Cho said that Trump’s leadership is “essential” to creating new opportunities with North Korea and that he expects “something to come out of President Trump’s leadership.”

But he acknowledged that the conflicting positions on denuclearization will require “a lot of back and forth” before there is a breakthrough.

 

September 2025
By Xiaodon Liang

Russia will cease abiding by its unilateral moratorium on the deployment of ground-launched intermediate-range missiles, six years after its president, Vladimir Putin, first announced the measure and invited the United States to reciprocate following U.S. withdrawal from the Intermediate-Range Nuclear Forces (INF) Treaty in 2019.

The United States and its NATO allies almost immediately rejected the offer on the grounds that Russia already had deployed missiles barred by the INF Treaty in violation of its own moratorium. But in a later exchange of proposals in December 2021 and January 2022, Washington indicated its willingness to begin new discussions with Russia on restrictions on the deployment of ground-launched intermediate and medium-range missiles. (See ACT, March 2022.)

As originally formulated by Putin in 2019, the unilateral moratorium bound Russia not to deploy previously barred INF-range missiles in “any given region until U.S.-made intermediate-range and shorter-range missiles are deployed there.” The variant offered by Russia as a proposed agreement in December 2021 instead suggested that the United States and Russia not deploy the missiles “either outside their national territories or inside their national territories from which the missiles can strike the national territory of the other party.”

Russia’s recent abandonment of its moratorium was announced Aug. 4 by the Russian Foreign Affairs Ministry in a statement observing that the United States had “made significant progress in the practical implementation [of ] … openly declared plans to deploy U.S. ground-launched INF-range missiles in various regions.”

In April, Russian Deputy Foreign Minister Sergei Ryabkov said deployment of U.S. missiles in Europe and Asia would trigger a withdrawal of the moratorium offer. At the time, the U.S. Army was deploying its “Typhon” Mid-Range Capability ground-launched missile system to the Philippines for exercises. (See ACT, May 2024.)

The Aug. 4 statement notes the Philippine deployment, as well as the recent participation by Typhon-equipped troops in multinational exercises in Australia in July.

The Typhon integrates a variant of the Mk-41 vertical launch system (VLS)—a standardized launcher aboard many U.S. and allied naval vessels that is capable of supporting numerous types of missiles—with supporting ground equipment. The Russian statement also noted a second derivative of the Mk-41 VLS, the Mk-70 Mod 1 Payload Delivery System.

The Mk-70, a containerized variant of the Mk-41 VLS launcher, was deployed by the U.S. Navy in a September 2023 exercise to the Danish island of Bornholm. In December 2024, the Navy announced that many littoral combat ships would be equipped with Mk-70 containers.

By design, both the Typhon and the Mk-70 are capable of launching the Tomahawk medium-range cruise missile. In a ground-launched configuration, this missile would have been banned by the now-defunct INF Treaty, which eliminated all Russian and U.S. ground-launched missiles with medium and intermediate ranges between 500 and 5,500 kilometers

German Defense Minister Boris Pistorius announced July 14 that Berlin had informed Washington of its interest in purchasing Typhon missile launchers for the German armed forces. He said that Washington is reviewing a U.S.-German agreement announced last year, whereby the United States would deploy its own Typhon-equipped forces in Germany along with the new Long-range Hypersonic Weapon (LRHW), Reuters reported. The LRHW made its first foreign deployment, to Australia in July.

The U.S. military has not yet test-launched a Tomahawk missile from a Mk-70, although the containerized launcher’s commonality with the Mk-41 strongly suggests it would be capable of supporting the cruise missile. Manufacturer Lockheed Martin describes the containerized launcher as providing “mid-range precision fires capabilities.”

The U.S. Army’s Rapid Capabilities and Critical Technologies Office, which led the development of the Typhon system, issued a solicitation for a third mobile Tomahawk-launcher design. In a June 27 contracting notice, the office described its interest in acquiring four prototypes of a Common Autonomous Multi-Domain Launcher, Heavy for the medium-range cruise missile. The Marine Corps is also pursuing integration of Tomahawk launchers with ground vehicles.

The Russian statement also highlighted concerns with the U.S. Precision Strike Missile (PrSM), which was tested to a range beyond its original design maximum of 499 kilometers in October 2021. The PrSM is a replacement for the Army Tactical Missile System and is designed to be fired from the M142 High Mobility Artillery Rocket System (HIMARS) launcher.

The Russian statement observed that, under the terms of the now-defunct INF treaty, the use of HIMARS to test PrSM means that all HIMARS launchers would fall under the treaty’s prohibitions.

Russia has been expanding its own arsenal of intermediate-range weapons, beyond the 9M729 cruise missile which originally triggered U.S. withdrawal from the INF Treaty. (See ACT, January/February 2019.) The Wall Street Journal reported in 2019 that the United States had informed allies that four battalions of the 9M729 missile had been deployed, and open-source analysis by the Federation of American Scientists indicate it is possible that since then, Russia has constituted a fifth battalion.

In October 2020, Putin suggested an exchange of inspections accompanying the moratorium to verify that the 9M729 missile was not deployed in the Russian exclave of Kaliningrad. In return, he requested inspections of Aegis Ashore missile defense launchers in Romania and Poland to confirm that they are incapable of firing offensive missiles. (See ACT, November 2020.) Before withdrawing from strategic stability talks with Russia in response to the full-scale invasion of Ukraine, the United States said it was willing to discuss transparency measures.

Speaking Aug. 1 on a visit to Belarus, Putin said serial production of the Oreshnik intermediate-range ballistic missile, first used in combat against Ukraine in November, had begun. His Belarusian counterpart, Alexander Lukashenko, said preparations for deployment of the new missile in Belarus would be completed this year, with deployments in 2026.

Belarus and Russia will conduct joint exercises in September to plan for the use of Oreshnik, Belarussian Defense Minister Viktor Khrenin said Aug. 13, according to Reuters. The two military forces also will conduct exercises on planning the use of nuclear weapons, the minister said.

September 2025
By Shizuka Kuramitsu

Japanese officials marked the 80th anniversary of the U.S. atomic bombing by reiterating their country’s long-standing commitment to a nuclear-weapon-free world, despite a growing domestic willingness to reconsider this policy.

Speaking Aug. 6 and Aug. 9, when the United States in 1945 attacked Hiroshima and then Nagasaki, Prime Minister Shigeru Ishiba reiterated Japan’s commitment to uphold the “three non-nuclear principles” and to “lead the efforts of the international community to bring about a world without nuclear war” and “a world without nuclear weapons.”

The two bombs, wielding a fraction of the power of today’s weapons, are roughly estimated to have killed around 215,000 people by the end of 1945.

“The widening of the division within the international community over approaches to nuclear disarmament has made the current security environment even more challenging. But that is exactly why we must make all-out efforts” toward disarmament, Ishiba added.

Under the 1960 U.S.-Japan Security Treaty, the United States committed to provide an extended deterrence to Japan by guaranteeing the use of U.S. military capabilities, including nuclear forces, to counter enemy threats.

Over the years, Japan and the United States have upgraded their alliance consultation and communications procedures related to extended deterrence. (See ACT, September 2024 and ACT, December 2024.)

More recently, the two countries have discussed scenarios involving the use of U.S. nuclear weapons in simulated contingencies involving Taiwan, Kyodo news agency reported July 26 and 27.

According to the reports, during their tabletop exercises, officials of Japan’s Self-Defense Force “repeatedly urged the U.S. force to make a nuclear threat” to counter a scenario in which China’s implied the use of nuclear weapons.

Recent polls suggest a slight shift among the Japanese population on the nuclear weapons issue. After a new 125-member Japanese lower house was elected July 20, a survey by Mainichi Shimbun showed that eight members support Japan’s acquisition of nuclear weapons. Although the number reflects a minority, it shows a shift from zero or one nuclear weapon supporter, which was a number recorded in the last survey in 2022, the newspaper reported.

Meanwhile, a member of the Japanese ruling party’s upper house and former deputy defense minister, Rui Matsukawa, in an interview with Reuters Aug. 20, “rais[ed] the possibility of Japan reducing its reliance on American security guarantees” and suggested that “Plan B is maybe [to] go independent, and then go [to] nukes.”

Reuters also reported that although “Support in Japan for developing its own indigenous atomic weapons is smaller [than South Korea] … interviews with a dozen Japanese lawmakers, government officials and former senior military figures reveal there is a growing willingness to loosen Japan’s decades-old pledge, formulated in 1967, not to produce, possess or host nuclear weapons in its territory—what is knowns as the three non-nuclear principles.”

Amid growing cynicism and some interests in exploring nuclear sharing and possession among the Japanese public, Hiroshima Governor Hidehiko Yuzaki warned in an Aug. 6 speech that “nuclear deterrence has not been safely sustained over the past 80 years, but has, at times, been on the brink of collapse.”

“Should nuclear deterrence fail someday, as suggested by historical evidence, and should nuclear war occur, it would be impossible to save the human race and the Earth from unrecoverable devastation,” Yuzaki said.

“What is the meaning of national security if it protects only the concept of a nation but has the possibility to lead unrecoverable end for its land and people?” he asked.

At the Aug. 9 ceremony, Nagasaki Mayor Shiro Suzuki called for “the government of Japan, the only nation to have suffered wartime atomic bombings… to firmly uphold the three non-nuclear principles.”

He also appealed to the leaders gathered in Nagasaki “to go back to the keystone values of the Charter of the United Nations, and restore multilateralism and the rule of law.”

He also noted that this year marks the 80th anniversary of the creation of the UN under the resolution to “save succeeding generations from the scourge of war.”

September 2025
By Lipi Shetty

The U.S. House Committee on Foreign Affairs approved six bills July 22 aimed at loosening controls on arms exports through amendments to the Arms Export Control Act or the process by which it is implemented in the interagency export control process.

On a party-line vote of 27 to 23, the committee approved H.R. 3613, the Streamlining Foreign Military Sales Act of 2025, which increases the dollar thresholds that foreign arms sales must reach before they trigger congressional notification requirements.

The bill doubles the threshold for non-NATO, non-Five Eyes countries from $14 million to $30 million, and nearly quadruples the thresholds for NATO and Five Eyes countries from $25 million to $105 million. The Five Eyes countries—Australia, Canada, New Zealand, the United Kingdom, and the United States—have a special commitment to share the most sensitive intelligence.

The bill goes beyond the change requested by the Trump administration in an Apr. 7 letter to Congress. Signed by Secretary of State Marco Rubio and Defense Secretary Pete Hegseth, the letter asked Congress to raise the current $25 million threshold for NATO allies to $55 million or more, Politico reported. The letter and bill follow Trump’s Apr. 9 executive order that eliminated certain agency regulations to expedite foreign arms sales. (See ACT, April 2025.)

“This bill represents one of the largest rollbacks of congressional oversight on arms sales in the last 50 years,” said Colby Goodman, a senior researcher with Transparency International U.S.

Goodman said the bill would not accelerate arms sales because “bureaucratic holdups [in the arms sales process] stem largely from within the Executive Branch, not from Congress.”

Also on a party-line vote, the committee cleared H.R. 3068, a bill to promote the AUKUS defense agreement among Australia, the UK and the United States. The bill, which passed 26 to 24, was sponsored by Rep. Bill Huizenga (R-Mich.) and co-sponsored by Rep. Michael McCaul (R-Texas), a co-chair of the Congressional Friends of Australia Caucus.

The bill modifies provisions of the Arms Export Control Act to permit the government to exempt rockets and unmanned aerial vehicles with a range of over 300 kilometers and capable of carrying over 500 kilograms of payload from licensing requirements through binding bilateral agreements.

The AUKUS agreement envisions the joint development of hypersonic missiles under “Pillar 2” of the trilateral defense partnership.

“By modernizing the Missile Technology Control Regime to meet the security challenges of today, we can strengthen our defense capabilities and increase our cooperation with our allies, especially Australia and the United Kingdom,” said Huizenga. H.R. 3068 “can act as a force multiplier that allows the United States and our closest allies to address the security challenges we face today and in the future.”

Three other bills about the arms trade passed the committee on a largely bipartisan basis. These included measures to modify previous legislation creating an expedited review process for AUKUS-related export licenses, to direct a review of the foreign military sales list, and to direct a prioritization of customers for direct commercial sales. A final bill, accelerating arms sales to countries in the Middle East and North Africa that recognize Israel and oppose Iran, passed the committee with a mix of Republican and Democratic votes.

September 2025
By Shizuka Kuramitsu

The United Kingdom is rapidly bolstering its nuclear deterrent by strengthening its capabilities and ties with allies, including expanding nuclear cooperation with France, reintroducing the U.S. gravity nuclear bomb on its territory, and acquiring U.S.-made nuclear-capable aircraft.

On July 18, open-source researchers on social media, including OSINTDefender, identified flight activity strongly suggesting that the U.S. Air Force delivered a batch of U.S. B61-12 nuclear gravity bombs to a newly upgraded storage facility at the UK Royal Air Force base at Lakenheath for the first time since at least 2005.

The return of U.S. nuclear gravity bombs has been anticipated since at least April 2022, when the Federation of American Scientists released a report flagging future upgrades to a nuclear weapons storage site at Lakenheath in U.S. defense budget documents. In February 2024, the BBC reported upgrades to the Lakenheath facility.

“The U.S. Air Force used to store nuclear gravity bombs at Lakenheath, which in the 1990s was equipped with 33 underground storage vaults. By the early 2000s, there were a total of 110 B61 gravity bombs in the vaults for delivery by F-15E aircraft of the 48th Fighter Wing,” Hans Kristensen of the Federation of American Scientists wrote in 2022.

If return of B61-12 bombs to the UK “were to happen, it would break with decades of policy and planning and reverse the southern focus of the European nuclear deployment that emerged after the end of the Cold War,” Eliana Johns and Hans Kristensen wrote in February 2025.

“Even without weapons present, the addition of a large nuclear air base in northern Europe is a significant new development that would haven inconceivable just a decade-and-a-half ago,” they wrote.

This development follows the recent announcement of the UK-French nuclear coordination as well as the UK announcement about joining NATO’s air-based nuclear mission by purchasing U.S. F-35A nuclear-capable fighter jets, to be based at Royal Air Force base at Marham. (See ACT, July/August 2025.)

French President Emmanuel Macron and UK Prime Minister Keir Starmer issued a joint statement on nuclear policy and coordination July 10 following a three-day state visit by Macron to the UK. Referred to as the Northwood Declaration, the text states an intention to deepen coordination on French and UK nuclear responses to “extreme threats” to the European continent. Although the countries will maintain ultimate control over their own nuclear arsenals, they noted that their “nuclear forces are independent, but can be coordinated.”

The declaration also establishes an oversight committee to facilitate alignment, called Nuclear Supervisory Group, which is responsible for coordinating on “policies, capabilities, and operations,” according to the July 10 report by Le Monde.

The renewed cooperation agreement between the only two European nations in possession of nuclear arsenals since the 1995 Chequers Declaration demonstrates a noteworthy bolstering of Europe’s independent nuclear capabilities. “This will not affect in any way the core elements of their respective national nuclear doctrines,” Bruno Tertrais, deputy director of the French Foundation for Strategic Research, wrote July 10 on X. “But I believe it’s the optimal step [France and the UK] could take in the current context.”

September 2025
By Shizuka Kuramitsu

After six years of secrecy, the Scottish government confirmed that the Royal Navy released radioactive water into Loch Long near Glasgow, due to its repeated failure to maintain a network of 1,500 water pipes at the Coulport armaments depot, the home base for the United Kingdom’s nuclear warheads.

According to the report co-published Aug. 9 by The Ferret and The Guardian, The Ferret obtained internal documents from the Scottish Government’s environmental watchdog, Scottish Environment Protection Agency (SEPA), in August, which “disclose that radioactive water drained into the loch, which is popular with swimmers, divers, kayakers and fishers, after a major flood in 2019.”

Thiry-three documents published by SEPA Aug. 5 disclosed for the first time the problems that the Royal Navy had been having with pipes bursting and flooding parts of the “Trident Special Area” at Coulport, “one of the most secretive, sensitive and secure areas in the UK.” The files indicate that one pipe burst at Coulport in 2010, two burst in 2019, and two more burst in 2021.

The UK navy base Clyde at Faslane and the armaments depot at Coulport serve as the Royal Navy’s main presence in Scotland, where it is responsible for storing, processing, and maintaining key elements of the UK nuclear warheads for Trident submarines, a weapons processing facility, and missile bunkers. In 2019, 2023, and 2024, The Ferret “first made a freedom of information request for files on radioactive problems at Coulport and Faslane.”

The two newspapers reported that SEPA and the UK Defense Ministry sought to keep the documents secret for national security reasons, despite repeated inquiries by reporters since 2019. The government finally released the files on the orders of David Hamilton, the Scottish information commissioner, who polices Scotland’s freedom of information laws.

Speaking to The Guardian Aug. 9, the Scottish Green Party’s co-leader, Patrick Harvie, said that there “are few sites as dangerous and where an accident or shoddy maintenance could have such potentially catastrophic consequences.” He called for more transparency from the defense ministry.

The Ferret indicated Aug. 9 that the UK Defense Ministry “has clamped down on releasing information about the UK nuclear weapons programme, citing national security,” including censoring annual nuclear safety assessments reported in 2017. The Guardian reported in 2009 that “there had been leaks of radioactive coolant into the neighboring area, the Firth of Clyde from nuclear submarines in 2004, 2007, and 2008.”

According to the Aug. 9 report by The Ferret, both SEPA and the UK Defense Ministry claimed that there “have been no unsafe releases of radioactive material into the environment at any stage,” and that “the risk to the environment from effluent discharges is of no regulatory concern,” based on SEPA’s annual assessments.