"I actually have a pretty good collection of Arms Control Today, which I have read throughout my career. It's one of the few really serious publications on arms control issues."
– Gary Samore
Former White House Coordinator for Arms Control and WMD Terrorism
Weapons Research & Development

Keep Human Control Over New Weapons

April 2019


Michael T. Klare’s article “Autonomous Weapons Systems and the Laws of War” (ACT, March 2019) highlights important issues, but omits enormous strategic risks inhearent to the use of artificial intelligence (AI) in a role of command. In a war between major powers, both sides’ AI systems would be able to outperform humans in the application of game theory, similar to state-of-the-art poker-playing AI, which can now readily defeat the top human players. Nation-states would be tempted to endow these genius-level autonomous killing systems with the authority to escalate, bringing the risk of bad luck causing misunderstandings that
lead to uncontrolled escalation.

Exacerbating the risk of near-instant autonomous escalation is the risk of an AI system deciding that it, unlike a human, may have nothing to lose. A human commander might be a father or mother who might choose to put the preservation of the human race above nationalistic warmongering. Recall how Soviet air defense officer Stanislav Petrov (a father of two) saved the world in 1983 by choosing to disbelieve a computerized system that claimed a U.S. nuclear first strike was in progress. His decision may have included a desire to put mercy over patriotism and not to participate in the annihilation of the human race.

Unfortunately, an AI system would have no such qualms. An AI system might or might not be trained with a self-preservation instinct. If not, it would not care if it is destroyed, and it could take needless risks, carelessly bluffing and escalating, seeking to make the adversary back down through suicidal brinksmanship.

One might think, therefore, that it is important to endow battlefield AI systems with a self-preservation instinct, but the consequences of doing so could be even worse. Once a weaponized AI system is given a self-preservation instinct, it may become impossible to shut down, as it would kill anyone who tried to shut it off, including its own country’s military or government leaders.

These killings might play out in several ways. On a small scale, the system could limit its “self-defense” killings by targeting only the officials trying to disable the AI system. Worse, the AI system could try to preserve itself by threatening mutually assured destruction: if it ever suspected, even incorrectly, that its shutdown was imminent, the AI system could retaliate with the launch of nuclear weapons.

A dying AI system, still energized for a few milliseconds by the last electrical charge remaining in its internal capacitors, could even nuke not just its own nation but the entire surface of Earth.

Jonathan Rodriguez founded Vergence Labs in 2011, which developed computerized smartglasses. Vergence was acquired by Snap Inc., where he is now manager of new device prototyping.



Michael T. Klare’s article “Autonomous Weapons Systems and the Laws of War” (ACT, March 2019) provides an excellent overview of the risks of the military uses of autonomous weapons. We need some kind of international control to ensure that autonomous military technologies obey the laws of war and do not cause inadvertent escalation. The Convention on Certain Conventional Weapons (CCW) offers the best chance for meaningful regulation.

Klare identifies three strategies for regulating autonomous weapons: a CCW protocol banning autonomous weapons, a politically binding declaration requiring human control, and an ethical focus arguing that such weapons violate the laws of war. I would add two other strategies: a CCW protocol short of prohibition and a prohibition negotiated outside of the CCW, the way the 1997 Mine Ban Treaty grew out of CCW negotiations.

Of these five strategies, a new CCW protocol provides the best hope for mitigating the risks. While a total prohibition would be preferable, it might be more realistic to agree on a set of regulations, such as a requirement that a human operator always be available to take over. Anything short of a new, legally binding treaty would likely be too weak to influence the states most interested in deploying autonomous weapons, while a treaty negotiated outside the CCW would likely be too restrictive.

To prevent arms race that Klare describes, any method for controlling autonomous weapons will need the buy-in of the countries with the most advanced autonomous weapons programs, and they are currently very skeptical of any control. A politically binding declaration or an appeal to the Hague Convention’s Martens Clause might have normative power, but that will not be enough to deter many states from seeking the military advantages that autonomous weapons could offer.

While reaching an agreement in the consensus-based CCW will be difficult, negotiating a treaty outside the CCW will likely be impossible. Given the success of groups like Human Rights Watch in achieving the Mine Ban Treaty and CCM, an agreement controlling autonomous weapons in some way can be completed. What remains to be seen is whether such an agreement will be enough to change the trajectory we are currently on.

Lisa A. Bergstrom is a technology and security specialist in Berkeley, Calif.





Keep Human Control Over New Weapons

Pentagon Asks More for Autonomous Weapons

April 2019
By Michael Klare

The Defense Department is seeking sharp spending increases to its autonomous weapons programs, according to the fiscal year 2020 budget request submitted to Congress in March. The request reflects a concerted drive to prepare U.S. military forces for possible high-intensity combat with rivals Russia and China. All three nations have expanded efforts to develop autonomous systems, artificial intelligence (AI), and hypersonic weapons. (See ACT, March 2019.)

The Navy is seeking to build four unmanned submarines based on this prototype vessel, the Echo Voyager. (Image: Boeing)The Pentagon request asks for a nearly tenfold increase to the Navy’s spending on large unmanned surface vehicles, from $49 million in 2019 to $447 million in 2020. The Army aims to boost robotics development from $74 to $115 million. All told, the Pentagon plans to spend $3.7 billion on unmanned systems in fiscal year 2020, plus $0.9 billion on AI systems and $2.6 billion on hypersonic weapons.

These added investments in advanced technologies are needed, officials claim, to counter Russia and China in the highly contested environments expected of future wars. “This is about looking at the future differently than we’ve looked at the past,” said Army Lt. Gen. Anthony Ierardi, the joint staff’s director of force structure, at a March 12 Pentagon briefing on the 2020 budget proposal. “It is an acknowledgment that we need to start to consider other ways of operating to enhance our lethality, as our adversaries adapt and change their ways of operating.”

The Navy stands out from the other services for its strong emphasis on developing AI-empowered unmanned systems, such as unmanned surface, underwater, and aerial vehicles. Such systems are needed, the Navy says, to augment its combat punch in hotly contested areas at lower cost and with fewer casualties.

The most striking item in the Navy’s 2020 budget proposal is the request for unmanned surface vehicles, specifically the design and production of two combat-ready, ocean-going vessels. This new program, says the Navy, will be “designed to provide low-cost, high-endurance, reconfigurable ships able to accommodate various payloads for unmanned missions and augment the Navy’s manned surface fleet.” Although details are sketchy (the Navy may be unsure of exactly what it wants) the proposed vessel is intended to undertake many of the same missions of traditional surface warships but without a human crew. A prototype vessel, the Sea Hunter, was largely intended for anti-submarine warfare, but the new proposed vessel will also provide “anti-surface warfare and strike capacity,” notes the Pentagon’s arms acquisition request for 2020.

In addition, the Navy is seeking to begin deploying unmanned undersea vehicles, or unmanned submarines. In February, it awarded $43 million to Boeing to build four Orca extra-large unmanned undersea vehicles. These 51-foot-long vessels, derived from Boeing’s Echo Voyager diesel-electric submersible, are designed to travel up to 6,500 nautical miles autonomously and to perform a variety of combat missions, including anti-submarine and anti-surface warfare.

The defense budget request seeks considerable funding to develop unmanned aerial vehicles. The Navy, for example, intends to spend $671 million in 2020, up from $519 million in 2019, on the MQ-25 Stingray, a drone aircraft intended for aircraft carrier-based operations. Once deployed, the Stingray will be used for a variety of functions, including aerial refueling and reconnaissance missions. The Air Force is testing the concept of an armed unmanned aerial vehicle designed to accompany F-15 and F-35 aircraft in combat, possibly to attack enemy air defense systems or to shield piloted aircraft from enemy fire. Under its Low-Cost Attritable Aircraft Technology program, the Air Force conducted the first flight test of its XQ-58A Valkyrie drone of this type on March 5 at Yuma Proving Grounds, Ariz.

The research, development, test, and evaluation section of the defense budget request contains additional requests for spending on AI systems, robotics, hypersonics, and other advanced technologies. The Army’s request for robotics development, for example, rises to $115 million in 2020 after receiving $38 million in 2018 and $74 million in 2019. Combined spending by the Army and Air Force on hypersonic weapons aims to increase from $509 million in 2019 to $804 million in 2020. Large sums are also sought under such vague headings as “emerging technologies” and “advanced technology development,” typically showing large increases in 2020 over previous years.

Official statements supporting the budget request indicate that the Pentagon plans to rush procurement of new autonomous weaponry despite promises to devise ethical principles for using such systems. In January, the Pentagon’s Defense Innovation Board announced an initiative to solicit public and professional views to help forge a “set of principles for developing, testing, and deploying” AI systems. (See ACT, March 2019.) Its recommendations are expected this summer, but no budget request documents mention the board’s effort.

U.S. presses forward on funding autonomous weapons while not mentioning ethics of use.

Germany Seeks Control for New Weapons

Potentially dangerous emerging technologies require a new multilateral approach to prevent their misuse, German Foreign Minister Heiko Maas told a March 15 security conference in Berlin.

German Foreign Minister Heiko Maas has proposed an international approach to control dangerous new weapons technologies. (Photo: Odd Andersen/AFP/Getty Images)“New technologies are far more susceptible to proliferation, manipulation, and misuse than conventional weapons,” he said. “The question is whether we are in control of technology or whether ultimately it controls us.”

Maas outlined a four-part approach “to rethink arms control.” First, citing the risk of automated conflicts escalating quickly out of control, he called for creating rules to ban fully autonomous weapons systems and to require ensure effective human control over all lethal weapons systems. (See ACT, March 2019.)

Second, he urged establishing an international dialogue about the swift advancements and proliferation of missile technology, including to nonstate actors who “already have access to short-range missiles.”

Third, Maas called for “articulating universal behavioral norms and standards in cyberspace” to protect the common interests of the international community.

Lastly, Maas highlighted concerns about the biotechnology sector and announced that Germany would “work to establish a permanent body of experts and scientists under the umbrella of the Biological Weapons Convention” to analyze risks and recommend action.—SASHA PARTAN

Germany Seeks Control for New Weapons

Controversy Over Nuclear Safety Board Scope and Size

Overlooked but significant controversies have been simmering about an independent government board in charge of overseeing safety standards and practices at the Department of Energy’s nuclear weapons complex, and the battle for independent oversight between the board and the agency. These issues are made all the more concerning against the backdrop of the Trump administration’s costly and expanding plans to recapitalize the U.S. nuclear weapons complex and increase the production of plutonium cores for nuclear weapons. In May 2018, the Energy Department issued Order 140.1 , which would change...

U.S. Nuclear Modernization Programs

August 2018

Contact: Kingston Reif, Director for Disarmament and Threat Reduction Policy, (202) 463-8270 x104

Updated: August 2018


Cost Overview

The United States maintains an arsenal of about 1,650 strategic nuclear warheads deployed on Intercontinental Ballistic Missiles (ICBMs), Submarine-Launched Ballistic Missiles (SLBMs), and Strategic Bombers and some 180 tactical nuclear weapons at bomber bases in five European countries.

The Congressional Budget Office (CBO) published a major report in October 2017 that estimates the nuclear weapons spending plans President Donald Trump inherited from his predecessor will cost taxpayers $1.2 trillion in inflation-adjusted dollars between fiscal years 2017 and 2046. This amounts to about 6 percent of all spending on national defense anticipated for that period, as of President Barack Obama’s final budget request to Congress in February 2016. When the effects of inflation are included, the 30-year cost would approach $1.7 trillion, according to a projection by the Arms Control Association.

The CBO estimate captures spending on the triad of nuclear delivery systems and command and control systems at the Defense Department and on nuclear warheads and their supporting infrastructure at the Energy Department’s semi-autonomous National Nuclear Security Administration (NNSA). Nearly every element of the U.S. nuclear arsenal is slated to be upgraded over the next 20 years. Most of these efforts are in the early stages, and a few others have yet to begin.

Other nuclear-armed states, notably Russia and China, are upgrading their arsenals and have tested, produced, and deployed more brand new systems than the United States over the past decade. But the U.S. military has upgraded and refurbished nearly all of its existing strategic and tactical delivery systems and the warheads they carry to last well beyond their originally planned service life and is now in the early stages of replacing many of these aging systems with new systems. Though decades old, these modernized forces are more capable than the originals and the new systems will include additional capability upgrades. The current and planned U.S. financial investment in nuclear forces is unrivaled by any other nuclear power.

Gen. Paul Selva, the Vice Chairman of the Joint Chiefs of Staff, noted in testimony to the House Armed Services Committee in March 2017 that while Russia and China continue to modernize their nuclear forces, "we [the United States] do have a qualitative advantage." 

The Trump administration, as outlined in its Nuclear Posture Review (NPR) released on Feb. 2, 2018, intends to continue the modernization plan laid out by the Obama administration, and also develop several new nuclear weapons capabilities that will add to the price tag for nuclear forces, including the near-term development of a low-yield submarine-launched ballistic missile (SLBM) and the longer-term development of new nuclear submarine-launched cruise missile (SLCM).

The NPR acknowledges that the upgrade costs are “substantial” but claims that nuclear weapons will consume no more than 6.4 percent of the defense budget. This projection does not include the cost of the new capabilities proposed in the review nor the major costs that must be borne by NNSA to upgrade nuclear warheads and their supporting infrastructure.

The CBO estimates that annual spending on nuclear weapons will peak at about $50 billion during the late 2020s and early 2030s. During this period, nuclear weapons would consume about 8 percent of total national defense spending and 15 percent of the Defense Department’s acquisition costs. The CBO estimate includes the full cost to sustain and upgrade long-range strategic bombers.

White House and Pentagon officials and defense budget watchers have expressed concern that the current triad modernization plans may not be executable in the absence of significant and sustained increases to overall military spending in the coming 15-20 years, in large part due to the fact that nuclear costs are scheduled to rise and overlap with a large "bow wave" in projected spending on conventional weapon system modernization programs, as well as rising personnel and readiness costs.

Former head of U.S. Strategic Command Gen. Robert Kehler said in November 2017 that he is "skeptical that we are capable of remaining committed to a long-term project like this [nuclear modernization] without basically messing with it and screwing it up."

The 2011 Budget Control Act puts in place caps on military spending through 2021. According to the CBO, in the long-term an aging population, rising health care costs, and the rising interest on the national debt will constrain the amount of funding available for discretionary spending, including defense spending, if tax revenues do not increase significantly. However, the Bipartisan Budget Act of 2018 increased the FY 2018 cap for national defense spending by $80 billion to $269 billion and increased the FY 2019 cap by $85 billion to $647 billion. Regardless, pressure on the defense budget and the implicit trade-offs within that budget are likely to persist into the 2020s and 2030s. 

For FY 2019 President Trump requested $11 billion to fund NNSA's nuclear weapons activities. This represents a massive 19 percent increase over the FY 2017 appropriation and reflects the direction in the NPR to significantly expand the agency’s work to prepare the United States to develop, test, and deploy new nuclear weapons and to increase the size of the nuclear stockpile. According to former deputy NNSA administrator Madelyn Creedon, “The biggest challenge laid out in the 2018 report is the new assignment for the NNSA.”

A U.S. Government Accountability Office report issued last year, warned that the “NNSA’s plans to modernize its nuclear weapons do not align with its budget, raising affordability concerns.” And former agency administrator Frank Klotz said in a Jan. 23 interview just two days after leaving office that the agency is “working pretty much at full capacity.”

Nuclear Modernization Snapshot

The overall nuclear modernization effort includes: 

  • Modernized Strategic Delivery Systems: Existing U.S. nuclear delivery systems are undergoing continual modernization, including complete rebuilds of the Minuteman III ICBM and Trident II SLBM. The service lives of the Navy’s 14 Trident Ohio-class ballistic missile submarines are being extended. Additionally, a new submarine, the Columbia class, which will replace the Ohio-class ballistic missile submarines, is undergoing development and is expected to cost about $128 billion to develop, according to the Defense Department. The B-2 strategic bomber, a relatively new system, is being upgraded, as is the B-52H bomber. The Air Force is also planning a new strategic bomber, the B-21, and a new nuclear-capable cruise missile, known as the Long-Range Standoff Weapon (LRSO) to replace the existing Air-Launched Cruise Missile (ALCM).
  • Refurbished Nuclear Warheads: The U.S. stockpile of nuclear warheads and bombs is continually refurbished through NNSA’s Life Extension Program (LEP). Existing warheads are certified annually to be safe and reliable. The NNSA is currently pursuing a controversial and expensive plan to consolidate the existing number of nuclear warhead types from 10 down to 5, although this program has been delayed. Known as the "3+2" strategy, the five LEPs associated with this approach are estimated to cost over $60 billion.
  • Modernized Production Complex: The nuclear weapons production complex is being modernized as well, with new facilities planned and funded. For example, the FY 2019 NNSA budget request includes $703 million for the Uranium Processing Facility (UPF) at Oak Ridge, Tennessee. The total construction cost for UPF is estimated at $6.5 – 7.5 billion, according to an independent study conducted by the Corps of Engineers, although some estimates put the price tag at $11 billion. NNSA has pledged to complete construction by 2025 for $6.5 billion.
  • Command and Control Systems: The Defense Department maintains command, control, communications, and early-warning systems that allow operators to communicate with nuclear forces, issue commands that control their use, and detect or rule out incoming attacks. The department plans to spend $40.5 billion on these activities between FY 2017 and FY 2026. This estimate is probably understated as the Pentagon is still developing its plan for modernizing these systems. In addition, the 2018 NPR calls for placing greater attention and focus on sustaining and upgrading command and control capabilities. 
  • Nuclear Force Improvement Program: In the wake of revelations of professional and ethical lapses and poor morale in the U.S. nuclear force, Defense Secretary Chuck Hagel announced in November 2014 steps the department is taking to address the numerous setbacks. These include changing the conduct of inspections to reduce the burden on airmen and sailors, eliminating micromanagement of nuclear personnel seen as overtaxed by excessive bureaucratic and administrative requirements, and elevating the head of Air Force Global Strike Command, which oversees the Air Force’s nuclear forces, from a three- to a four-star rank.

Nuclear Modernization Overview

The following is a status update of existing programs to enhance the nuclear stockpile and modernize the delivery systems that make up each element of the U.S. nuclear triad:

1. Intercontinental Ballistic Missiles (ICBMs) 

The United States Air Force currently deploys about 400 Minuteman III ICBMs (as of February 5, 2018) located at F.E. Warren Air Force Base, Wyoming; Malmstrom Air Force Base, Montana; and Minot Air Force Base, North Dakota. U.S. nuclear-armed ICBMs are on high alert, meaning the missiles can be fired within minutes of a presidential decision to do so. Under the New START treaty, the United States maintains 50 extra missile silos in a "warm" reserve status.

Today's Minuteman weapon system is the product of almost 40 years of continuous enhancement. The Pentagon has spent over $7 billion over the past 15 years on life extension efforts to keep the ICBMs safe, secure and reliable through 2030. This modernization program has resulted in an essentially "new" missile, expanded targeting options, and improved accuracy and survivability. 

Ground-Based Strategic Deterrent

The Air Force is planning to replace the Minuteman III missile, its supporting launch control facilities, and command and control infrastructure. The Air Force intends to purchase over 600 missiles, 400 of which would be operationally deployed through 2070. The remaining missiles would be used for test flights and as spares. The replacement program is known as the Ground-Based Strategic Deterrent (GBSD). The service is seeking to make significant capability upgrades as part of the recapitalization program. The Pentagon in August 2016 set the estimated acquisition cost of the program at $85 billion and the total life-cycle cost at $238 billion (in then-year dollars). The $85 billion estimate is at the lower-end of an independent Pentagon cost-estimate that put the acquisition price tag as high as $140 billion.

For FY 2019, the Trump administration requested $345 million for the program, a 60 percent increase over 2018.  On Aug. 21, 2017, the Air Force awarded contracts to both Boeing Company and Northrop Grumman to continue development and begin design of the new ICBM system.

W78 and W87 Warheads

The Air Force has also upgraded the Minuteman’s nuclear warheads by partially replacing older W78 warheads with newer and more powerful W87 warheads, formerly deployed on the now-retired MX Peacekeeper ICBMs. The W87 entered the U.S. stockpile in 1986, making it one of the newest warheads in the arsenal with the most modern safety and security features, including insensitive high explosive and a fire-resistant pit design, which can help to minimize the possibility of plutonium dispersal in the event of an accident. Under a 2004 LEP, the W87 warhead was refurbished to extend its service life past 2025.

NNSA has proposed a joint LEP to field a common, refurbished warhead to replace the W78 and W88 (see SLBMs, below). Congress approved NNSA's 2014 proposal to delay production of this warhead by five years from 2025 to 2030. However, the 2018 NPR proposes to accelerate the program by one year and the FY 2019 budget request would provide $53 million for the project.

2. Submarine-Launched Ballistic Missiles (SLBMs) and Submarines

The United States Navy deploys, as of February 2018, 203 Trident II D5 SLBMs on 12 Ohio-class ballistic missile submarines (SSBNs) based out of Bangor, Washington (7 boats) and Kings Bay, Georgia (5 boats). The Ohio-class submarines have a service life of 42 years — two twenty-year cycles with a two-year mid-life nuclear refueling. The total fleet includes 14 boats but due to the refueling process, only 12 SSBNs are operational at any given time. Four to five submarines are believed to be "on station" in the Atlantic and Pacific oceans ready to fire their missiles at targets at any given time.

The Ohio-class SSBNs were first deployed in 1981, and will reach the end of their services at a rate of approximately one boat per year between 2027 and 2040. The Navy plans to replace each retiring boat, starting in 2031, with a new class of ballistic missile submarine, now referred to as the Columbia class. The Navy originally planned to begin using the replacement boats in 2029, but in 2012 the Pentagon announced a two-year delay to the replacement program. This pushed back completion of the first new submarine to 2031.

Taking into account the delay, the Navy now plans to purchase the first Columbia class submarine in 2021, the second in 2024, and one per year between 2026 and 2035. The first vessel is scheduled to become operational in 2031. As a result, the Navy will field 10 ballistic missile submarines between 2030 and 2040. 

In its FY 2019 request, the Navy asked for $3.7 billion for the Columbia class program — a 97 percent increase over 2018, making it the second-most expensive program in the 2019 Pentagon budget request, next to the F-35 Joint Strike Fighter. The Navy ultimately wants 12 boats, and in 2017 estimated the cost to develop and buy the submarines to be $128 billion in then-year dollars at the total life-cycle cost to be $267 billion. However, a report on the Columbia class program published by the Government Accountability Office (GAO) in December 2017 warned that the program is not adequately funded to address program risks and that the acquisition cost is likely to exceed $128 billion.

Under New START, each Ohio-class submarine serves as a launch platform for up to 20 SLBMs loaded with up to eight warheads each, or 240 total SLBMs. The Columbia class will carry up to 16 SLBMs, for a maximum of 192 deployed SLBMs when the fleet is fully converted to the new boats in 2040.

Trident II D5 Submarine-Launched Ballistic Missiles

First deployed in 1990, the force of Trident II D5 missiles has been successfully tested over 160 times since design completion in 1989 and is continuously evaluated. (By contrast, Russia's newest SLBM, the Bulava, has failed in roughly half its flight tests.) The Trident II D5 LEP is underway to modernize key components, notably the electronics, and extend the life of the missile until 2042. In 2008, 12 life-extended variants of the D5 were purchased; 24 D5s were produced each year through 2012 for a total of 108 missiles at a total cost of $15 billion. The first modified D5s were deployed in 2013. The Navy’s FY 2019 budget request includes a proposed $1.23 billion to fund the Trident II LEP. 

The Pentagon has yet to establish replacement program of record for the Trident II (D5), development of which is likely to begin in the 2020s.

W76 and W88 Warheads

The D5 SLBMs are armed with approximately 768 W76 and 384 W88 warheads. In 2009, NNSA began delivery of the W76-1, a refurbished version of the W76 that extends its service life for an additional 30 years. NNSA plans to complete the $4 billion production of up to 2,000 W76-1 warheads by 2019. NNSA requested $114 million for the W76 life extension program for FY 2019, down from $222 million the year before. 

The W88 entered the stockpile in 1989, making it the newest warhead in the arsenal. The W88 was the last U.S. warhead produced before the Rocky Flats Plants - which made plutonium "pits" - was shut down in 1989. NNSA re-established pit production capacity at Los Alamos National Laboratory with the first "certifiable" pit in 2003, and new production resumed in 2007. A new plutonium research and pit production facility, the Chemistry and Metallurgy Research Replacement Nuclear Facility (CMRR-NF), was planned for Los Alamos, but was put on hold for budget reasons in 2012. 

With the rebuilt Trident D5 missile in service to 2042, the W76-1's life extended to 2040-50, the relatively new W88 in service, and a new class of SSBNs lasting into the 2070s, the U.S. Navy’s Trident Fleet will be kept robust and modern deep into the 21st century.

3. Strategic Bombers

The United States Air Force currently maintains 13 deployed B-2 Spirit bombers at Whiteman Air Force Base in Missouri, and 36 deployed B-52H bombers at Minot Air Force Base, North Dakota, and Barksdale Air Force Base, Louisiana, that can be equipped for nuclear missions as of September 2017.  

Projected spending on nuclear weapons modernization programs could account for as much as 19% of estimated Pentagon modernization spending over the next 15 years, according to a recent analysis of 120 planned major Defense Department acquisition programs. (Source: Todd Harrison, CSIS)

B-52H Bomber

The B-52H fleet, first deployed in 1961, has an on-going modification program, beginning in 1989, incorporating updates to the global positioning system, updating the weapons capabilities to accommodate a full array of advanced weapons developed after the procurement of the B-52H, and modifying the heavy stores adapter beams to allow the B-52H to carry up to 2,000 pound munitions and a total of 70,000 pounds of mixed ordnance armaments. In FY 2011 the Air Force added to its modernization efforts for the B-52H, receiving funding for the Combat Network Communications Technology (CONECT) program, which updates the B-52 computer infrastructure. The upgrade is projected to cost a total of $1.1 billion.

The B-52H is expected to remain in service until 2040. 

B-2 Bomber

The Air Force continually modernizes the B-2 fleet, which first became operational in 1997 and is expected to last through 2058.

Ongoing B-2 modifications include an incremental three-part program to update the Extremely High Frequency Satellite Communications and Computer Upgrade program (EHF SATCOM). Increment 1 will upgrade the B-2’s flight management computers. Increment 2 provides more secure and survivable strategic communications by integrating the Family of Beyond-Line-of-Sight Terminals with the low observable antenna. Increment 3 connects the B-2 with the Global Information Grid. The Air Force also began procuring components for a Radar Modernization Program (RMP) in FY 2009. The RMP includes replacing the original radar antenna and upgrading radar avionics.

The Air Force announced in February 2018 that "once sufficient B-21 aircraft are operational, the B-1s and B-2s will be incrementally retired."

B-21 Bomber

The Air Force is planning to purchase at least 100 new, dual-capable long-range penetrating bombers that will replace the B-1 and B-52 bombers. Known as the B-21, the Pentagon estimates the average procurement unit cost per aircraft will be between $546 million and $606 million (in Fy 2016 dollars). Fielding is slated to begin in the mid- 2020s. The Trump administration requested $2.3 billion for the program in FY2019. The Air Force plans to spend $38.5 billion between FY 2017 and FY 2026 on research and development for the new bomber (in then-year dollars). The Air Force has refused to release the value of the contract awarded to Northrop Grumman Corp. in October 2015 to begin developing the B-21 program and the estimated total cost of the program, citing classification concerns.

The CBO estimates the B-21 program will cost $97 billion (in FY 2017 constant dollars).

Air-Launched Cruise Missile and Long-Range Standoff Cruise Missile

The B-52H carries the air-launched cruise missile (ALCM), first deployed in 1981. Each ALCM carries a W80-1 warhead, first produced in 1982. The Air Force retained roughly 570 nuclear-capable ALCMs as of the spring of 2015. Roughly 200 of these missiles are believed to be deployed at Minot Air Force Base in North Dakota with the W80-1 nuclear warhead. 

Some reports indicate that the reliability of the ALCM could be in jeopardy due to aging components which are becoming increasingly difficult to maintain.

The Air Force is developing the long-range standoff cruise missile (LRSO) to replace the existing ALCM. The new missile will be compatible with the B-2 and B-52H bombers, as well as the planned B-21. The first missile is slated to be produced in 2026. The LRSO would carry the refurbished W80-4 warhead.

The current Air Force procurement plan for the LRSO calls for about 1,000 new nuclear-capable missiles, roughly double the size of the existing fleet of ALCMs. According to the service, the planned purchase of 1,000 missiles includes far more missiles than it plans to arm and deploy with nuclear warheads. For FY 2019, NNSA requested $654 million for the W80-4, making it the second-most expensive nuclear warhead, next to the B61-12. In addition,  the Air Force requested $615 million for development of the LRSO missile.

The Pentagon projects the cost to acquire the new missile fleet at about $11 billion (in then-year dollars) and the cost to operate and sustain the missile fleet over its expected life at over $6 billion (in constant FY 2016 dollars). The Energy Department projects the cost of the life extension program for the ALCM warhead to be between $8 billion and $11.6 billion (in then-year dollars).

B61 and B83 Warheads

The B-2 carries the B61 and B83 strategic gravity bombs. The B61 has several mods, 3, 4, 7, 10, and 11. B61-3 and B61-4 are non-strategic weapons deployed in Europe for NATO aircraft as part of America’s extended nuclear commitment.

The B61-7 and B61-11 are strategic weapons deployed on the B-2 bomber. An LEP recently extended the life of the B61-7 for an additional 20 years by refurbishing the bomb’s secondary stage (canned subassembly) and replacing the associated seals, foam supports, cables and connectors, washers, o-rings, and limited life components. The ongoing B61 LEP would combine mods 3, 4, and 7 into a single bomb, the B61 mod 12. The B61-12 is slated to begin production in 2020 and will refurbish the bomb  with new firing, arming, and safety components, updated radar components, permissive action link components and equipment, modified power supplies, thermal batteries, join test assemblies, weapon trainers, and test and handling gear.  The LEP will also modify the B61 for compatibility with the F-35 Joint Strike Fighter. The LEP will extend the life of the B61s for 20-30 years.

An updated assessment of the B61 life extension program (LEP) performed by the NNSA in 2016 put the direct cost of the program at $7.6 billion, an increase of $200 million over the agency’s estimate of $7.4 billion provided in its fiscal year 2017 budget materials. The NNSA’s independent Office of Cost Estimating and Program Evaluation, however, told the GAO that its assessment of the program projects a total cost of approximately $10 billion and a two-year delay to the agency’s estimated March 2020 first production-unit date. NNSA requested $794 million for the B61 LEP in FY 2019. 

The upgraded B61 will be equipped with a new tail-kit guidance assembly that will make the bomb more accurate and allow it to have a lower yield than some of the existing variants. The new tail kit is being developed by the Air Force and is estimated to cost $1.3 billion.

The B83 was first produced in 1983, making it one of the newer weapons in the stockpile and the only remaining megaton-class weapon in the stockpile. The B83 has the most modern safety and security features, including insensitive high explosive and a fire-resistant pit. 

The Obama administration stated that the B83 would be retired once confidence in the B61 mod 12 is projected to be achieved in the mid 2020s. However, the Trump NPR reverses this decision and calls for retaining the B83 until a suitable replacement is found.


Department of Defense Programs


Modernization Plan


Length of Deployment

Additional Information

Minuteman III ICBM

Modernization and Replacement Program

$7 billion

through 2030 

Modernizes the propellant, guidance systems, propulsion system, targeting system, reentry vehicles and continues work on the rocket motors


Replace the Minuteman III missile and associated launch control and command and control facilities

$85-$140 billion (DoD estimate; FY 2017-2046)


Air Force plans to purchase over 600 new ICBMs

B-2 Bomber

Modernization Program

$9.5 billion (FY 2000-2014)


Improves radar and high frequency satellite communications capabilities for nuclear command and control

B-52H Bomber

On-going modifications



Incorporates global positioning systems, updates computers and modernizes heavy stores adapter beams, and a full array of advance weapons

Long Range Strike Bomber (B-21)

Research and development phase

$38.5 billion (FY 2017-2026)


The exact specifications of the new bomber are classified

Long Range Standoff Cruise Missile (LRSO)

Replacement for the ALCM

$20 billion (estimated; includes cost of W80-4 warhead refurbishment)


Air Force plans to procure ~1,000 LRSOs

Columbia Class SSBN (SSBN(X))

New ballistic missile submarine

$128 billion (2016 Navy acquisition estimate)

2031 - 2080s

Navy plans to purchase 12 new submarines to replace the existing 14 Ohio-class submarines

Trident II D5 SLBM LEP

Modernization and life extension

$6 billion (FY 2019-2023



Strategic Arms Control and Policy

Trump Sets INF Response Strategy

January/February 2018
By Kingston Reif

The Trump administration is increasing the pressure on Russia over its alleged violation of the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, confirming earlier press reports that its strategy to confront Moscow includes development of a new missile system that if built and tested would violate the accord.

Russian President Vladimir Putin, accompanied by Defense Minister Sergei Shoigu, visits the Peter the Great Strategic Missile Forces Academy near Moscow on December 22, 2017. Russia denies the U.S. claim that it is violating the 1987 Intermediate-Range Nuclear Forces (INF) Treaty. (Photo: MIKHAIL KLIMENTYEV/AFP/Getty Images)The State Department announced on Dec. 8, the 30th anniversary of the treaty, that the administration is “taking new diplomatic, military, and economic measures intended to induce the Russian Federation to return to compliance and to deny it any military advantage should it persist in its violation.” This action follows a policy review and Russia’s continued refusal to address U.S. compliance concerns.

The department said that beginning research on “concepts and options for conventional, ground-launched, intermediate-range missile systems,” which is not prohibited by the treaty, “will prepare the United States to defend itself and its allies.”

The United States will cease this research if Russia “returns to full and verifiable compliance” with the treaty, the department added.

Russia, which denies it has violated the treaty, responded harshly to the announcement. “It looks like conditions are being set ... for the United States to walk out on” the treaty, Russian President Vladimir Putin said at his annual year-end news conference Dec. 14.

Lawmakers voted in November to require the Defense Department to establish a program to begin development of a new ground-launched cruise missile (GLCM) having a range prohibited by the treaty as part of the fiscal year 2018 National Defense Authorization Act. (See ACT, December 2017.)

Some members of Congress have raised concerns about a tit-for-tat response, arguing that it could lead to a dangerous and unnecessary missile race in Europe. A bipartisan group of 13 senators wrote to the leaders of the Senate Appropriations Committee on Dec. 8 urging them to prohibit the expenditure of fiscal year 2018 funds on a new GLCM. “We believe the development of such a missile would call into question the United States' commitment to uphold” its long-standing obligations under the treaty, they stated in the letter.

Neither the House nor Senate appropriations committee-approved versions of the fiscal year 2018 defense appropriations bill include funding for a new GLCM. Republican and Democratic lawmakers have yet to pass a final spending bill for the current fiscal year.

If the United States decides to deploy the new missiles, development would likely take years and cost several billion dollars.

Foreign ministers of NATO countries gather for a meeting of the North Atlantic Council in Brussels Dec. 6, 2017. The council issued a statement Dec. 15 saying the report of a new Russian missile system “raises serious concerns.” (NATO photo)The Trump administration said it will also continue to seek a diplomatic resolution, including through the treaty’s dispute resolution forum known as the Special Verification Commission (SVC), and pursue punitive economic measures against “entities involved in the development and manufacture of Russia’s prohibited cruise-missile system.”

The SVC met for the 31st time in Geneva on Dec. 12-14. It is not clear whether the meeting made progress or whether the parties agreed to meet again.

A State Department press release on Dec. 14 said the parties to the treaty “expressed the view that the INF Treaty continues to play an important role in the existing system of international security, nuclear disarmament and non-proliferation, and that they will work to preserve and strengthen it.”

Since 2014, Washington has accused Moscow of violating its commitment “not to possess, produce, or flight-test” a GLCM having a range prohibited under the pact. In the past year, the Pentagon has alleged publicly that Russia is fielding a noncompliant system.

The INF Treaty requires Russia and the United States to eliminate permanently their nuclear and conventional ground-launched ballistic and cruise missiles having ranges of 500 to 5,500 kilometers.

The Obama administration explored a range of military options to respond to Russia’s alleged violation, but ultimately decided to pursue a broader approach that went beyond its specific concerns about Moscow’s noncompliance with the treaty. (See ACT, January/February 2016.)

In announcing its new approach, the Trump administration for the first time revealed both the U.S. name for the missile of concern, the SSC-8, and the apparent Russian designation, the 9M729.

In a Dec. 9 statement, Russian Deputy Foreign Minister Sergey Ryabkov called the U.S. charges “totally unfounded” and reiterated Russia’s position that the United States is violating the agreement. Washington maintains that it is in full compliance.

Although previous Russian denials have not acknowledged the existence of the missile system in question, Ryabkov said the Trump administration had provided Russia with the name of a “missile research project” but that the missile is compliant with the treaty.

Meanwhile, NATO, which since 2014 has been reluctant to strongly condemn Russia for violating the treaty, said in a Dec. 15 statement that member states had identified a Russian missile system that “raises serious concerns” and called on Russia “to address these concerns in a substantial and transparent way, and actively engage in a technical dialogue with the United States.”

NATO’s actions, “including national measures taken by some allies, seek to preserve the INF Treaty, strengthen the alliance, and incentivize Russia to engage in good faith,” the statement added.

The Trump administration is increasing the pressure on Russia over its alleged violation of the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, confirming earlier press reports that its strategy to confront Moscow includes development of a new missile system that if built and tested would violate the accord.

‘Killer Robot’ Debates Planned

At the annual meeting of the UN Convention on Certain Conventional Weapons (CCW), delegates from 91 states agreed to continue formal deliberations on the use of lethal autonomous weapons systems, the technology often popularly called “killer robots,” at two conferences this year.

The Defender, an experimental robotic platform able to perform reconnaissance, surveillance, and targeting tasks, is shown in a 2008 photo. The system was designed to be operated remotely by military personnel, although technology advances could make possible a similar system able to operate autonomously. (U.S. Air Force photo)The first meeting of the CCW group of governmental experts on these systems, which included interested states-parties and civil society groups, met on Nov. 13-17 in Geneva to discuss the topic for the first time in a formal session. Annual informal meetings of experts had been convened to discuss the systems from 2014 to 2016. The fifth review conference of the CCW in December 2016 established a formal group to meet in 2017 with a mandate to “explore and agree on possible recommendations” regarding the emerging technologies. (See ACT, January/February 2017). The experts group decided to extend its mandate and hold two more one-week sessions this year. The full conference of the CCW, which met in Geneva on Nov. 22-24, affirmed that decision.

Many nongovernmental groups advocating for a ban on lethal autonomous weapons systems welcomed the extension, but expressed frustration at the lack of progress in negotiating any legal instruments despite growing concerns among civil society groups, scientists, and parliamentarians. The Campaign to Stop Killer Robots, an international coalition, said in a Nov. 24 statement that it “remains disappointed that all countries seem able to do is roll-over the previously agreed mandate and meet for just 10 days during 2018. This decision does not reflect a sense of urgency.”

According to the group, 22 states now support a legally binding instrument to pre-emptively prohibit these systems before they are deployed by any states. China, Israel, Russia, the United Kingdom, and the United States are among the countries developing the technology.—MACLYN SENEAR

‘Killer Robot’ Debates Planned

ACA-YPFP NextGen Voices: The Untold Story in the Nuclear Nonproliferation Saga



What: Short Film "Marshalling Peace" and
NextGen Discussion

When Tuesday, August 29

Where1619 Massachusetts Ave NW
Washington, D.C. 20036 

On August 29 - the International Day Against Nuclear Testing - ​NextGen filmmaker Autumn Bordner joins Young Professionals in Foreign Policy (YPFP) and the Arms Control Association for a​n exclusive​ showing of Marshalling Peace​. Autumn traveled to the Marshall Islands to research the lingering effects of U.S. nuclear testing conducted there during the Cold War. Her short film documents the tiny nation's legal battle against nuclear weapons​-holding superpowers​, and the​ devastating effects of the U.S. nuclear testing program on the Marshallese people.

Autumn and the Association's Executive Director Daryl Kimball will facilitate a discussion on the future of nuclear weapons threats and the ways NextGen leaders can shape today's and tomorrow's nuclear policies. YPFP's Danielle Preskitt (a former Association intern) will moderate.

The Panelists:

Autumn Bordner is a rising second year at Stanford Law School. Prior to matriculating at Stanford, Autumn worked as an environmental consultant at ICF, and as a fellow with the K1 Project, Center for Nuclear Studies, a research institute that she co-founded as an undergraduate at Columbia University. Autumn is also a member of the Comprehensive Test Ban Treaty Organization (CTBTO) Youth Group. In this capacity, she is working to advance the entry into force of the Comprehensive Nuclear Test Ban Treaty.

Daryl G. Kimball became the Executive Director of the Arms Control Association in September 2001. The Arms Control Association is a private, non-profit membership organization dedicated to public education and support of effective arms control measures pertaining to nuclear, chemical, biological, and conventional weapons. Find his complete bio here.



ACA and Young Professionals in Foreign Policy (YPFP) are hosting an event featuring a​n exclusive​ showing of Marshalling Peace and a discussion on the future of nuclear weapons threats and the ways NextGen leaders can shape today's and tomorrow's nuclear policies.

Board Backs Off Lower-Yield Nukes

April 2017

By Charles J. Carrigan

Members of the Defense Science Board told Congress that the advisory group’s recent report on the potential utility of “lower yield” nuclear weapons was not intended as advocating U.S. production of such weapons.

The civilian technical experts, who testified March 9 before the House Armed Services strategic forces subcommittee, sought to tamp down controversy stirred by the group’s December 2016 report, “Seven Defense Priorities for the New Administration.”

Defense Science Board members Michael Anastasio and Miriam John testify March 9 before the House Armed Services strategic forces subcommittee. (Photo credit: House Committee on Armed Services)The part of the 76-page report that drew attention was brief language on the need to increase the flexibility of the U.S. nuclear arsenal, citing lower-yield weapons as a “hedge for future uncertainties.” The path to flexibility includes what the report called lower-yield, “primary only options” that could provide a “tailored nuclear option for limited use, should existing non-nuclear or nuclear options prove insufficient.”

It is a sensitive issue because critics warn that such tactical weapons lower the threshold for nuclear conflict and suggest there is a viable option for limited nuclear war.

Board member Michael Anastasio, a former director of the Los Alamos National Laboratory, said the panel intended only to suggest that the U.S. nuclear enterprise have the flexibility and capability to produce such weapons if a policy decision were made that they are needed. The board had tried to “distinguish between the technical capability of this enterprise versus the policy questions,” he testified.

In the wake of the report, Sen. Dianne Feinstein (D-Calif.) and 12 other Senate Democrats wrote March 14 to Defense Secretary James Mattis and Energy Secretary Rick Perry expressing opposition to building a new, lower-yield nuclear weapon. “We strongly believe there is no such thing as the limited use of nuclear weapons or limited nuclear war,” they wrote.

“For 71 years, the United States has led the world in opposition to the use of nuclear weapons, leadership that would be called into question should the United States develop new, so-called low-yield nuclear weapons,” they wrote.

The issue is complicated by Russia’s evolving “escalate to de-escalate” doctrine, which envisions its limited use of tactical nuclear weapons during a conflict in a show of determination intended to force the United States to back down to avoid full-scale nuclear war. The report includes a reference to the doctrine in a section that examined the reasons for continued U.S. development of deterrent capabilities.

At the hearing, board member Miriam John, retired vice president of Sandia National Laboratories facility in Livermore, Calif. emphasized the need to ensure that the technical flexibility will exist to produce such weapons. “If there’s a military need, then the [enterprise] will respond, but there is no military requirement,” she said. When asked to clarify that there is not a need for such tactical nuclear weapons, she responded by just saying, “Today.”

Another controversial part of the report suggested that the United States may need to resume underground nuclear testing at some point to advance “scientific understanding” and ensure the reliability of the nuclear stockpile. “It is my view, and I think the view of the Defense Science Board, that we do not need nuclear testing right now,” Anastasio clarified in his testimony.

The United States ended nuclear testing in September 1992 and has relied on the Stockpile Stewardship Program to maintain and modernize nuclear weapons without the need for explosive testing. Although noting the capabilities of that program, the report says that “an open question remains as to how long one can have confidence in the weapons” through this approach.

The senators, in their letter, offered strong opposition to consideration of renewed testing. “We do not believe it is an ‘open question,’ as the board claims, whether the science-based Stockpile Stewardship Program and associated nuclear warhead life extension programs can maintain our confidence in the long-term reliability of our nuclear deterrent,” they wrote.

“Additionally, in 2015, the three nuclear weapons lab directors reported that the country was in a better position to maintain the nuclear arsenal than it was during the era of test explosions, which ended more than 20 years ago,” they wrote. “We strongly believe that the United States does not need to resume nuclear testing, which will only encourage others to do the same. Instead, we should seek to reinforce the global norm against nuclear weapons testing.”

The Defense Science Board report drew strong pushback from Senate Democrats.

Congressional hearings reveal “no military requirement” for new low-yield weapons

Witnesses with military, policy and technical expertise all rejected the notion of a “military requirement” for new low-yield weapons in a series of hearings before the House and Senate Armed Services Committees March 8 and March 9. This evident agreement among experts from a range of positions and backgrounds should demonstrate to Congress that there is little credible argument for the additional development of low-yield nuclear weapons, despite language in a December 2016 Defense Science Board report recommending the development of such weapons. The Defense Science Board is an advisory body...


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