When the Soviet Union collapsed in 1991, the fate of its vast nuclear and chemical weapons arsenals was unclear. Four post-Soviet states—Russia, Belarus, Kazakhstan, and Ukraine— inherited operational nuclear forces, prompting immediate questions of command and control, ownership, storage, and security. After the United States and Russia, Ukraine became the world's third largest nuclear state, with more than 1,900 warheads on its territory.

"Ukraine was the key nation, and U.S. policy emphasized nonproliferation, arms control treaties, and security assistance," said Joseph P. Harahan, a senior historian at the U.S. Department of Defense and currently a Wilson Center fellow. "Russia, seeking to become the Soviet Union's sole nuclear successor state," he explained, "objected to Ukraine retaining its inherited nuclear rocket army and bomber forces." Ukraine's government, after months of indecision, decided its nuclear forces could be powerful bargaining chips in securing its sovereignty and assisting its failing economy.

In the early 1990s, Russian, Ukrainian, and U.S. leaders engaged in intense diplomacy to resolve the nuclear issue. In the Trilateral Agreement of 1994, Ukraine relinquished its nuclear weapons and warheads, ratified the START and NPT treaties, and became a non-nuclear weapons nation. Russia provided Ukraine with $1 billion worth of fuel rods for its civilian nuclear plants, and $2.6 billion in oil and gas credits as compensation. The United States provided financial and technical assistance that enabled Ukraine to transport the warheads to Russia, and to develop joint projects that dismantled and liquidated every strategic missile and long-range bomber.

Harahan is writing a history that will explain how the United States, Russia, Ukraine, Kazakhstan, and Belarus developed and managed a multi-year, multi-billion dollar cooperative threat reduction (CTR) program. "The CTR program," he said, "was and is a means to an end for the United States." The means are an array of cooperative assistance projects focused on dismantling strategic weapons and facilities, securing and safeguarding nuclear warheads, and eliminating excess nuclear and chemical weapons. The ends are the non-nuclear status of Ukraine, Belarus, and Kazakhstan, and the continuing engagement of the Russian Federation. From 1992-2005, the United States provided some $7.2 billion in CTR assistance to Russia, Belarus, Ukraine, and Kazakhstan.

In this post-Cold War effort, the leadership of Senators Sam Nunn and Richard Lugar was instrumental. For more than a decade, Nunn and Lugar persuaded Congress to appropriate $400 million per year in assistance. Harahan said, "Both the Clinton and Bush administrations used this assistance program as one element in their foreign policy strategy for the entire region." To date, under the CTR program, the United States has helped these nations deactivate 6,564 nuclear warheads, eliminate 568 strategic missiles, 476 missile silos, 140 strategic bombers, 28 nuclear submarines, 480 submarine missile launchers, 541 submarine missiles, and seal 194 nuclear test tunnels.

"Cooperation on this scale takes time, presence, and flexibility," Harahan said. "Governments can collaborate successfully if they have the leadership and discipline to stay focused over many years."