Ukraine destroyed its last SS-24 ICBM silo on October 30, making it the third START I party to complete its obligations under the accord.
Belarus and Kazakhstan both met their obligations under the agreement in late 1996. The United States and Russia are not yet in full compliance, according to the most recent information available, but they must become so by December 5. At that time, Washington and Moscow must each deploy no more than 6,000 treaty-accountable nuclear warheads on 1,600 strategic delivery vehicles.
The United States and the Soviet Union signed the START I agreement in July 1991, but the Soviet Union dissolved five months later, leaving four successor states in possession of nuclear weapons: Russia, Belarus, Ukraine, and Kazakhstan.
In May 1992, these four countries, along with the United States, signed the Lisbon Protocol, which designating them as successors to the Soviet Union under START I. The protocol also obligated Ukraine, Belarus, and Kazakhstan to transfer their nuclear warheads to Russia and to join the nuclear Non-Proliferation Treaty as non-nuclear-weapon states.
But Ukraine proved reluctant to give up its nuclear weapons and ultimately required additional inducement. Under a January 1994 agreement with the United States and Russia, Ukraine agreed to give up its nuclear weapons in exchange for security assurances, compensation for the fissile material contained in its nuclear weapons, and financial assistance.
Ukraine announced in 1996 that it had finished transferring all its nuclear warheads to Russia, but it retained treaty-accountable strategic delivery vehicles, including bombers and ICBMs. The United States has assisted Ukraine with dismantling those delivery vehicles under the Defense Department’s Cooperative Threat Reduction program.