“Lugar and Obama traveled together to Russia, Ukraine and Azerbaijan in August 2005 to oversee a number of Nunn-Lugar projects. In Ukraine they saw a conventional weapons facility that is typical of the focus of the new legislation.
The Lugar-Obama initiative is modeled after the Nunn-Lugar program that focuses on weapons of mass destruction in the former Soviet Union. Lugar and former Senator Sam Nunn (D-GA) authored the program in 1991. It has provided U.S. funding and expertise to help the former Soviet Union safeguard and dismantle its enormous stockpiles of nuclear, chemical and biological weapons, related materials, and delivery systems. Among many accomplishments, the program has deactivated 7,000 nuclear warheads and reemployed 58,000 scientists in peaceful research. Ukraine, Belarus and Kazakhstan are nuclear weapons free as a result of cooperative efforts under the Nunn-Lugar program. They otherwise would be the world’s the third, fourth and eighth largest nuclear weapons powers, respectively.”
https://web.archive.org/web/20080617231047/http://obama.senate.gov/press/070111-lugar-obama_non
Well if Ukraine still had nuclear weapons, I doubt Russia would try invading Crimea.