The New Strategic Arms Reduction Treaty (New START) was signed April 8, 2010 in Prague by Russia and the United States and entered into force on Feb. 5, 2011. New START replaced the 1991 START I treaty, which expired December 2009, and superseded the 2002 Strategic Offensive Reductions Treaty (SORT), which terminated when New START entered into force.
New START continues the bipartisan process of verifiably reducing U.S. and Russian strategic nuclear arsenals begun by former Presidents Ronald Reagan and George H.W. Bush. New START is the first verifiable U.S.-Russian nuclear arms control treaty to take effect since START I in 1994.