Geopolitics › Global issues & flashpoints › Nuclear weapons and proliferation
New START expiry: no US–Russia nuclear limits
Feb 5, 2026· Treaty or event
FactTreaties, membership, measured data, events.
On February 5, 2026 the last US–Russia nuclear arms treaty expired, leaving the two largest arsenals without treaty limits for the first time in decades.
See it on the Geopolitics map →The picture
Signed in Prague in 2010, New START capped each side at 1,550 deployed strategic warheads and 700 deployed missiles and bombers, checked by on-site inspections. It was extended once, in 2021, to its final date. Russia suspended participation in 2023, halting inspections and data exchanges. In September 2025 Putin offered to observe the limits for a year if the US did too; no binding replacement followed. Both sides can now add warheads to existing missiles.
Why it matters
Without limits or inspections each side must assume the worst about the other, raising the risk of an arms race that now also includes a fast-growing China.
Key facts and numbers
The treaty text, US State Department compliance reports, Russian Foreign Ministry statements, and warhead estimates from the Federation of American Scientists and SIPRI.
What to watch
Outlook: whether either side 'uploads' extra warheads or quietly keeps to the old caps, and whether new talks can include China, which refuses.
Connections (2)
▸New START expiry: no US–Russia nuclear limits removed treaty limits on RussiaFact
The relationship
With New START gone, nothing legally caps Russia's deployed strategic warheads or lets US inspectors check them. Russia can load extra warheads onto missiles such as the Yars and Sarmat, and its newest systems, the Burevestnik cruise missile and Poseidon torpedo, were never covered by the treaty.
Since when and why
Expired February 5, 2026, after Russia suspended participation in February 2023; inspections had stopped in 2020.
How we know
The treaty's text and expiry date, Russian Foreign Ministry statements and US State Department reports on Russian compliance.
What to watch
Whether Moscow actually expands its deployed forces, or keeps to the old caps to save money and draw Washington into new talks.
▸New START expiry: no US–Russia nuclear limits may spur a three-way race with China (People's Republic of China)Outlook
The relationship
Outlook, not fact: without US–Russia limits, Washington may build up to deter two nuclear peers at once, Russia and a fast-growing China. Some US strategists urge more warheads; China cites the US and Russian arsenals, each still roughly eight to nine times its own, as reason to keep building and refuse talks.
Since when and why
Washington, Moscow and Beijing after February 5, 2026; a 2023 congressional Strategic Posture Commission urged preparing for two nuclear peers.
How solid?
This is an outlook resting on official statements, the 2023 commission report and Pentagon projections of over 1,000 Chinese warheads by 2030.
What to watch
Whether a three-way race actually starts, and whether Trump's calls for 'denuclearization' talks with Russia and China lead anywhere.