Following the dissolution of the Soviet Union in 1991, Ukraine and Russia continued to retain close ties. In 1994, Ukraine agreed to abandon its nuclear arsenal and signed the Budapest Memorandum on Security Assurances on the condition that Russia, the United Kingdom, and the United States would issue an assurance against threats or use of force against the territorial integrity or political independence of Ukraine. Five years later, Russia was one of the signatories of the Charter for European Security, where it "reaffirmed the inherent right of each and every participating State to be free to choose or change its security arrangements, including treaties of alliance, as they evolve".[1]