2010 nuclear arms reduction treaty between the United States and the Russian Federation
New START set binding limits on US and Russian strategic nuclear launchers and established a verification regime, representing a major step in post-Cold War arms control.
Key Facts
- Signing date
- 8 April 2010
- Entry into force
- 5 February 2011
- Treaty expiry
- 5 February 2026
- Effect on launchers
- Halved the number of strategic nuclear missile launchers
- Russia suspension
- Russia suspended participation on 21 February 2023
- Predecessor treaty
- Replaced Treaty of Moscow (SORT), due to expire December 2012
By the Numbers
Location
Cause → Event → Consequence
START I expired in December 2009 and the Treaty of Moscow was set to expire in December 2012, leaving a gap in the US-Russia nuclear arms control framework. Prior attempts including START II and START III had failed to enter into force, creating urgency for a new bilateral agreement to maintain limits on strategic nuclear arsenals.
On 8 April 2010, the United States and Russia signed New START in Prague. The treaty required both nations to halve their strategic nuclear missile launchers and established a new inspection and verification regime to replace that of SORT. It did not, however, restrict the stockpiling of operationally inactive nuclear warheads, which numbered in the high thousands.
New START entered into force on 5 February 2011 and governed US-Russian strategic nuclear arms for fifteen years. Russia suspended its participation on 21 February 2023 amid tensions over Ukraine, though it stated it would continue observing numerical limits. The treaty ultimately expired on 5 February 2026, leaving no successor agreement in place.
Political Outcome
Treaty signed and ratified; strategic nuclear missile launchers halved and new verification regime established; expired 5 February 2026 with no successor agreement.