Nuclear treaty between Russia and U.S. expires, raising arms-control concerns

The New START treaty between Russia and the United States expired on Thursday; Russia said it regretted the lapse and officials warned the loss of treaty limits could reduce transparency and raise risks.

The New START nuclear arms treaty between Russia and the United States expired on Thursday. The treaty had limited deployed strategic missiles, launchers and warheads and was the last remaining bilateral arms-control agreement. Russia said it regretted the expiry and announced it would act responsibly while protecting its national interests. U.S. officials said the president would decide the way forward and would "clarify on his own timeline." Key facts: - The New START treaty set limits on deployed strategic missiles, launchers and warheads and was the most recent remaining U.S.-Russia nuclear agreement. - Russia announced it regretted the treaty's expiry and said it would maintain a responsible approach while defending national interests. - The White House said the U.S. president will decide the next steps and will clarify the approach on his own timeline. - U.N. Secretary-General António Guterres said the lapse dissolves decades of arms-control achievements and warned that the risk of nuclear use is the highest in decades. Summary: The treaty's expiry removes a formal framework that promoted predictability between the two largest nuclear powers, and officials say reduced transparency could increase the risk of misunderstandings. The immediate legal effect is that New START limits no longer apply. Undetermined at this time.