US–Russia New START Treaty Expires, Ending Binding Limits on Strategic Nuclear Arms

Together, the United States and Russia possess nearly 90 percent of the world’s nuclear weapons.

A Russian Yars intercontinental ballistic missile system drives during the Victory Day Parade in Red Square in Moscow, Russia, on June 24, 2020. Iliya Pitalev/Reuters

The last remaining nuclear arms control treaty between the United States and Russia expired on Feb. 5, ending legally binding limits on the world’s two largest nuclear arsenals for the first time in decades.

The New Strategic Arms Reduction Treaty, known as New START, entered into force on Feb. 5, 2011, and was extended for five years in February 2021.