Budapest Memorandum

The Budapest Memorandum on Security Assurances comprises four substantially identical political agreements signed at the Conference on Security and Co-operation in Europe (CSCE) in Budapest, Hungary, on 5 December 1994, to provide security assurances by its signatories relating to the accession of Belarus, Kazakhstan and Ukraine to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The four memoranda were originally signed by four nuclear powers: Ukraine, Russia, the United States, and the United Kingdom. France and China gave individual assurances in separate documents.

The memoranda, signed in Patria Hall at the Budapest Congress Center with U.S. Ambassador Donald M. Blinken amongst others in attendance, prohibited Russia, the United States, and the United Kingdom from threatening or using military force or economic coercion against Ukraine, Belarus, and Kazakhstan, "except in self-defence or otherwise in accordance with the Charter of the United Nations". As a result of the memorandum and other agreements, between 1993 and 1996, Belarus, Kazakhstan, and Ukraine gave up their nuclear weapons. On 6 December the CSCE without mentioning the Budapest Memoranda per se published in the same conference hall the Budapest Summit Declaration and the Budapest Decisions, following which on 1 January 1995 it became known as the OSCE.

Russia violated the Budapest memorandum in 2014 with its annexation of Ukraine's Crimea and in 2022 by invading Ukraine. As a response, the United States, United Kingdom, and France provided Ukraine with financial and military assistance, and imposed economic sanctions on Russia, while ruling out "any direct interventions to avoid a direct confrontation with Russia".