From Guns.com:

Elected in November 2004 to the seat held by U.S. Sen. Peter Fitzgerald, Obama’s banner freshman effort on Capitol Hill was to expand the Nunn – Lugar Cooperative Threat Reduction concept – a disarmament program that destroyed Ukraine’s 1,240 nuclear warheads – to include conventional weapons like artillery, small arms, and tanks. As part of the move, Obama traveled to Eastern Europe just eight months after taking office, accompanying U.S. Sen. Dick Lugar to meet with Ukrainian officials about destroying their guns with America picking up the tab.