The Lisbon Protocol At a Glance

Last Reviewed
December 2020

Contact: Kingston ReifDirector of Disarmament and Threat Reduction Policy, (202) 463-8270 x104

A pervasive fear surrounding the collapse of the Soviet Union was the uncertain fate of its nuclear arsenal. In addition to Russia, the emerging states of Belarus, Kazakhstan, and Ukraine inherited a significant number of nuclear weapons, raising concerns that the Soviet Union would leave four nuclear weapon successor states instead of just one. Aside from increasing the number of governments with their finger on the proverbial nuclear button, the circumstances simultaneously raised concerns that those weapons might be more vulnerable to possible sale or theft. The Lisbon Protocol, concluded on May 23, 1992, sought to alleviate those fears by committing the three non-Russian former Soviet states to return their nuclear weapons to Russia. In spite of a series of political disputes that sparked some concerns about implementation of the protocol, all Soviet nuclear weapons were eventually transferred to Russia by the end of 1996.

When the Soviet Union officially dissolved in December 1991, the newly-independent states of Belarus, Kazakhstan, and Ukraine inherited more than 3,000 strategic nuclear weapons (those capable of striking the continental United States), as well as at least 3,000 tactical or battlefield nuclear weapons. In 1991, the United States and the Soviet Union announced the Presidential Nuclear Initiatives to substantially reduce their respective tactical nuclear weapons arsenals. All dispersed Soviet tactical weapons were reportedly back on Russian soil by the end of 1992, but the strategic weapons posed a larger problem.

The United States and Russia reached a solution to this complex problem by engaging Belarus, Kazakhstan, and Ukraine in a series of talks that led to the Lisbon Protocol. That agreement made all five states party to the 1991 Strategic Arms Reduction Treaty (START), which required Washington and Moscow to each cut their deployed strategic nuclear forces from approximately 10,000 warheads apiece to down below 6,000 warheads on no more than 1,600 intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and long-range bombers. The protocol signaled the intentions of Belarus, Kazakhstan, and Ukraine to forswear nuclear arms and accede to the nuclear Nonproliferation Treaty (NPT) as non-nuclear-weapon states, a commitment that all three fulfilled and continue to abide by today.

 

Estimated Warheads in Belarus, Kazakhstan, and Ukraine in 1991

 

Strategic Warheads

Tactical Warheads

Belarus

100

725

Kazakhstan

1,410

Uncertain

Ukraine

1,900

2,275

Sources: Robert S. Norris, “The Soviet Nuclear Archipelago,” Arms Control Today, January/February 1992, p. 24; and Joseph Cirincione, et al., Deadly Arsenals, Carnegie Endowment for International Peace, 2005, p. 366.

 

Basic Timeline and Provisions:

  • July 31, 1991: The United States and the Soviet Union sign START.
  • Dec. 31, 1991: The Soviet Union officially dissolves, delaying entry into force of START.
  • May 23, 1992: Russia, Belarus, Ukraine, Kazakhstan, and the United States sign the Lisbon Protocol.
    • Under the protocol, all five states become parties to START.
    • Belarus, Kazakhstan, and Ukraine promise to accede to the NPT as non-nuclear-weapon states “in the shortest possible time.”
  • July 2, 1992: Kazakhstan ratifies START.
  • Oct. 1, 1992: The U.S. Senate votes to give its advice and consent to ratification of START.
  • Nov. 4, 1992: The Russian State Duma refuses to exchange START instruments of ratification until Belarus, Ukraine, and Kazakhstan accede to the NPT.
  • Feb. 4, 1993: Belarus ratifies START.
  • July 22, 1993: Belarus submits its instrument of accession to the NPT as a non-nuclear-weapon state.
  • January 14, 1994: The Trilateral Statement is signed by U.S. President Bill Clinton, Russian President Boris Yeltsin, and Ukrainian President Leonid Kravchuk. It allows Ukraine to observe the transfer of weapons from its territory to Russia and the dismantlement of certain systems. It also commits Russia to send some of the uranium extracted from the returned warheads back to Ukraine for fuel.
  • Feb. 3, 1994: Ukraine ratifies START, rescinding conditions for ratification that it had issued in November 1993.
  • Feb. 14, 1994: Kazakhstan submits its instrument of accession to the NPT as a non-nuclear-weapon state.
  • Dec. 5, 1994: Ukraine submits its instrument of accession to the NPT as a non-nuclear weapon state.
    • The five START parties exchange instruments of ratification for START, which enters into force.
  • April 24, 1995: Kazakhstan transfers its last strategic weapon to Russia.
  • June 1996: Ukraine transfers its last strategic weapon to Russia.
  • November 1996: Belarus transfers its last strategic weapon to Russia, marking completion of Lisbon Protocol obligations.

Ratification and Implementation:

Belarus:

When the Soviet Union dissolved, the newly-established Republic of Belarus found itself in possession of roughly 800 total nuclear weapons deployed within its borders. Although Russia retained the warhead arming and launch codes, many worried that Belarus might attempt to take control of the weapons. Moreover, Belarusian President Alexander Lukashenko twice threatened to retain some weapons if NATO deployed nuclear weapons of its own in Poland. However, when a constitutional crisis erupted in November 1996, Lukashenko was finally compelled to finalize the transfers.

Minsk signed the Lisbon Protocol on May 23, 1992, ratified it on Feb. 4, 1993, and deposited its instrument of accession to the NPT as a non-nuclear-weapon state on July 22, 1993. By November 1996, all nuclear warheads in Belarus had been transferred to Russia.

Kazakhstan:

After gaining independence, Kazakhstan, with extensive U.S. technical and financial assistance, disposed of the strategic nuclear weapons that it inherited from the Soviet Union. Kazakhstan’s 1,410 strategic warheads were deployed on several different systems, including SS-18 ICBMs and cruise missiles carried by Bear-H bombers.

Kazakhstan’s parliament ratified START on July 2, 1992. All tactical nuclear weapons had been withdrawn to Russia by January 1992. The parliament approved accession to the NPT on Dec. 13, 1993, and deposited the state’s NPT instrument of ratification on Feb. 14, 1994. The last of the Kazakh-based strategic nuclear weapons were transferred to Russia by April 24, 1995.

Ukraine:

When the Soviet Union dissolved, Ukraine became the third-largest nuclear weapons power in the world behind the United States and Russia. Ukraine’s 1,900 strategic warheads were distributed among ICBMs, strategic bombers, and air-launched cruise and air-to-surface missiles. Although Ukrainian President Leonid Kravchuk signed the Lisbon Protocol on May 23, 1992, Ukraine’s process of disarmament was filled with political obstacles. Many Ukrainian officials viewed Russia as a threat and argued that they should keep nuclear weapons in order to deter any possible encroachment from their eastern neighbor. Although the government never gained operational control over the weapons, it declared “administrative control” in June 1992, and claimed in 1993 ownership of the warheads, citing the potential of the plutonium and highly enriched uranium they contained for creating peaceful energy.

A resolution passed by the Rada, the Ukrainian parliament, on Nov. 18, 1993, attached conditions to its ratification of START that Russia and the United States deemed unacceptable. Those stated that Ukraine would only dismantle 36 percent of its delivery vehicles and 42 percent of its warheads; all others would remain under Ukrainian custody. Moreover, the resolution made those reductions contingent upon assurances from Russia and the United States to never use nuclear weapons against Ukraine (referred to as “security assurances”), along with foreign aid to pay for dismantlement.

In response, the Clinton and Yeltsin administrations intensified negotiations with Kyiv, eventually producing the Trilateral Statement, which was signed on Jan. 14, 1994. This agreement placated Ukrainian concerns by allowing Ukraine to cooperate in the transfer of the weapons to Russia, which would take place over a maximum period of seven years. The agreement further called for the transferred warheads to be dismantled and the highly enriched uranium they contained to be downblended into low-enriched uranium. Some of that material would then be transferred back to Ukraine for use as nuclear reactor fuel. Meanwhile, the United States would give Ukraine economic and technical aid to cover its dismantlement costs. Finally, the United States and Russia responded to Ukraine’s security concerns by agreeing to provide security assurances upon its NPT accession.

In turn, the Rada ratified START, implicitly endorsing the Trilateral Statement. However, it did not submit its instrument of accession to the NPT until Dec. 5, 1994, when Russia, the United Kingdom, France, and the United States provided security assurances to Ukraine. That decision by the Rada met the final condition for Russia’s ratification of START and therefore subsequently brought that treaty into force.

For more information, see Ukraine, Nuclear Weapons and Security Assurances at a Glance.