The US-Russia nuclear treaty known as New START expired on February 5, marking the end of the last remaining arms control agreement between the two nuclear powers. The expiration removes binding limits on the number of strategic nuclear warheads deployed by Washington and Moscow.
The United Nations warned that the end of the US-Russia nuclear treaty represents a serious threat to international peace and security. Officials and analysts cautioned that the lapse could accelerate a new global arms race at a time of heightened geopolitical tensions.
New START Treaty Officially Expires
The New START agreement ended at midnight GMT, formally releasing both the United States and Russia from restrictions on their strategic nuclear arsenals. The treaty was signed in 2010 in Prague by then US president Barack Obama and Russian president Dmitry Medvedev.
Under the agreement, each country was limited to 1,550 deployed strategic nuclear warheads, nearly 30 percent fewer than the limits set under the previous 2002 accord. The treaty also allowed on-site inspections, although these inspections were suspended during the Covid-19 pandemic and never resumed.
UN Warns of Rising Nuclear Risks
UN Secretary-General Antonio Guterres described the expiration of the US-Russia nuclear treaty as a grave moment for international peace and security. He said the world is now facing a situation without any binding limits on the strategic nuclear arsenals of the two largest nuclear powers for the first time in more than half a century.
Guterres warned that the risk of a nuclear weapon being used is at its highest level in decades and urged Washington and Moscow to return to negotiations without delay to agree on a successor framework.
Russian and International Reactions
Russia’s foreign ministry said that both countries are no longer bound by obligations under the treaty. Moscow stated it intends to act responsibly but warned it would take decisive countermeasures if its national security is threatened.
Pope Leo XIV also urged both sides to do everything possible to prevent a new arms race. Speaking during his weekly audience, he called on the United States and Russia not to abandon the agreement without ensuring a concrete and effective follow-up.
H2: US Position and China Factor
President Donald Trump did not act on a proposal from Russian President Vladimir Putin to extend the treaty for one year. While Trump previously said the idea sounded reasonable, no negotiations followed.
US Secretary of State Marco Rubio said the administration believes any future arms control agreement must include China, citing Beijing’s rapidly expanding nuclear arsenal. China is estimated to have around 550 strategic nuclear launchers, compared with about 800 each for the United States and Russia under New START limits.
Analysts Question Negotiation Efforts
Arms control experts said that while China’s involvement is important, there is little evidence that the US administration has actively pursued talks with Beijing since Trump returned to office in 2025.
The treaty had previously been extended for five years in 2021 under President Joe Biden. Relations between Washington and Moscow later deteriorated sharply following Russia’s invasion of Ukraine.
Conclusion:
The expiration of the US-Russia nuclear treaty removes the last formal barrier limiting the world’s two largest nuclear arsenals. International leaders and experts warn that without renewed diplomacy, the risk of escalation and global instability will continue to grow.
