New START Treaty Goes Into Effect

Secretary of State Hillary Clinton exchanged ratification papers for the New START treaty with her Russian counterpart at a Munich conference today, sealing the deal on the nuclear arms treaty that limits the number of atomic warheads the former Cold War foes can possess and allows them to inspect each other's arsenals. New START was approved by the US Senate in December; Russia ratified the deal last month.

New START is a cornerstone of Obama's efforts to "reset" US relations with Russia, and Clinton called it a "milestone in our strategic partnership." "When it comes to the button that has worried us the most over the years—the one that would unleash nuclear destruction—today we take another step to ensure it will never be pushed," Clinton told reporters after the treaty went into effect. (More START Treaty stories.)