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Ukraine, Nuclear Weapons, and Security Assurances At a Glance

Last Reviewed: 
July 2017

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

At the time of Ukraine’s independence from the Soviet Union in 1991, Ukraine held the third largest nuclear arsenal in the world, including an estimated 1,800 strategic warheads, 176 long-range ballistic missiles, and 42 strategic bombers. By 1996, Ukraine had returned all of its nuclear warheads to Russia in exchange for economic aid and security assurances, and Ukraine became a non-nuclear weapon state party to the 1968 nuclear Nonproliferation Treaty (NPT). The last strategic nuclear delivery vehicle in Ukraine was eliminated in 2001 under the 1991 Strategic Arms Reduction Treaty (START). It took years of political maneuvering and diplomatic work, starting with the Lisbon Protocol in 1992, to remove the weapons and nuclear infrastructure from Ukraine.

1990 Declaration of Sovereignty

Partly in an effort to gain international recognition, Ukraine’s pre-independence movement supported efforts to join the NPT as a non-nuclear weapon state. With Ukraine’s July 16, 1990 Declaration of Sovereignty, Ukraine pledged “not to accept, produce, or acquire nuclear weapons." However, despite this public commitment, Ukrainian politicians were not entirely united by the idea. Some felt that Russia was a still a threat and that they should keep the weapons as a deterrent.

1991 Minsk Agreement on Strategic Forces

With the dissolution of the Soviet Union, the Commonwealth of Independent States signed the Minsk Agreement on December 30, 1991, agreeing that the Russian government would be given charge of all nuclear armaments. However, as long as the weapons remained in Belarus, Ukraine, and Kazakhstan, the governments of those countries would have the right to veto their use. The target date for dismantling the weapons was set for the end of 1994.

1992 Lisbon Protocol

Ukraine signed the Lisbon Protocol on May 23, 1992. The protocol sought to return the nuclear weapons in Belarus, Kazakhstan, and Ukraine to Russia. All states were to join START and the NPT. However, within Ukraine, there was little motion towards the ratification of START, joining the NPT, or overall denuclearization. The protocol required that Ukraine adhere to the NPT as quickly as possible, but it gave the country up to seven years to follow through.

By late 1992, the Ukrainian parliament was vocalizing more pro-nuclear views. Some believed that Ukraine was entitled to at least temporary nuclear weapon status. Perhaps optimistically, the U.S. government promised Ukraine $175 million in dismantlement assistance. Instead, the Ukrainian government began implementing administrative management of the nuclear forces and claimed ownership of the warheads.

In late April 1993, 162 Ukrainian politicians signed a statement to add 13 preconditions for ratification START, frustrating the ratification process. The preconditions required security assurances from Russia and the U.S., foreign aid for dismantlement, and compensation for the nuclear material. Additionally, they stated that Ukraine would dismantle only 36% of its delivery vehicles and 42% of warheads, leaving the rest under Ukrainian control. Russia and the U.S. criticized these demands, but Ukraine did not budge. In May 1993, the U.S. said that if Ukraine were to ratify START, the U.S. would provide more financial assistance. This began subsequent discussions between Ukraine, Russia, and the U.S. over the future of Ukrainian denuclearization.

1993 Massandra Accords

Ukrainian and Russian officials reached a set of agreements, including protocols on nuclear weapons dismantlement, procedure, and terms of compensation. However, the two sides could not agree on the final document, and the summit ultimately failed. 

1994 Trilateral Statement

The Massandra Accords set the stage for the ultimately successful trilateral talks. As the U.S. mediated between Russia and Ukraine, the three countries signed the January 14, 1994 Trilateral Statement. Ukraine committed to full disarmament, including strategic weapons, in exchange for economic support and security assurances from the United States and Russia. Ukraine agreed to transfer its nuclear warheads to Russia and accepted U.S. assistance in dismantling missiles, bombers, and nuclear infrastructure. Ukraine’s warheads would be dismantled in Russia, and Ukraine would receive compensation for the commercial value of the highly enriched uranium. Ukraine ratified the START treaty in February 1994, repealing its earlier preconditions, but it would not accede to the NPT without further security assurances.

1994 Budapest Memorandum on Security Assurances

To solidify security commitments to Ukraine, the United States, Russia, and the United Kingdom signed the December 5, 1994 Budapest Memorandum on Security Assurances. A political agreement in accordance with the principles of the Helsinki Accords, the memorandum included security assurances against the threat or use of force against Ukraine’s territory or political independence. The countries promised to respect the sovereignty and existing borders of Ukraine. Parallel memorandums were signed for Belarus and Kazakhstan as well. In response, Ukraine officially acceded to the NPT as a non-nuclear weapon state on December 5, 1994. That move met the final condition for ratification of the START treaty, bringing the treaty into force for Ukraine

2009 Joint Declaration by Russia and the United States

Russia and the United States released a joint statement in 2009 confirming that the security assurances made in the 1994 Budapest Memorandum would still be valid after the START Treaty expired in 2009.

2014 Russian Annexation of Crimea

Following months of political unrest and the abrupt departure of President Yanukovych of Ukraine, Russian troops entered the Crimean peninsula of Ukraine in March 2014. On March 18, over the protests of the acting government in Kiev, the UN Security Council, and Western governments, Russia declared the annexation of Crimea. The United States, the United Kingdom, and Ukraine called the action a blatant violation of the security assurances in the 1994 Budapest Memorandum. However, according to the Russian Ministry of Foreign Affairs, “the security assurances were given to the legitimate government of Ukraine but not to the forces that came to power following the coup d'etat.”


  • July 16, 1990: Ukraine’s Declaration of Sovereignty
  • July 31, 1991: The United States and the Soviet Union signed START.
  • Dec. 26, 1991: The Soviet Union officially dissolved, delaying entry into force of START.
  • Dec. 30, 1991: Minsk Agreement on Strategic Forces
    • The Commonwealth of Independent States agreed that strategic forces would be under the joint command of the former Soviet Union states.
  • May 23, 1992:  Lisbon Protocol
    • Signed by Russia, Belarus, Ukraine, Kazakhstan, and the United States
    • The protocol sought to return nuclear weapons in three formerly Soviet states to Russia.
    • All states were to be added to the START treaty and to join the NPT.
  • Jan. 14, 1994: The Trilateral Statement
    • Signed by Ukraine, Russia, and the United States
    • Ukraine committed to full disarmament, including strategic offensive weapons, in exchange for economic support and security assurances from US and Russia.
  • Sept. 4, 1993 Massandra Accords
    • Failed summit between Russian and Ukrainian governments
  • Dec. 5, 1994 Budapest Memorandum on Security Assurances
    • Signed by Russia, Ukraine, United States, and the United Kingdom
    • Included security assurances against the threat or use of force against Ukraine’s territory or political independence.
  • Dec. 5, 1994: Ukraine submitted its instrument of accession to the NPT as a non-nuclear weapon state.
    • The five START parties exchanged instruments of ratification for START, which entered into force.
  • June 1, 1996: Ukraine transferred its last nuclear warhead to Russia
  • October 30, 2001: Ukraine eliminated its last strategic nuclear weapon delivery vehicle.
  • Dec. 4, 2009: Joint Statement by Russia and the United States
    • The two countries confirmed that the security guarantees made in the 1994 Budapest Memorandum.
  • March 18, 2014: Russia annexed the Crimean peninsula

Research by Ashley Luer