On February 5, 2026, a treaty expired and nobody stopped the clock. New START, the last remaining legal constraint on US and Russian deployed strategic warheads, lapsed without a successor. Trump had rejected Putin's offer of a one-year extension. For the first time in over 35 years, the 2 largest nuclear arsenals on the planet operate under no mutual limits whatsoever. A Senate probe into the fallout launched this month. The Arms Control Association has a multilateral briefing scheduled for March 24. The institutional scramble tells you everything about how unprepared the world was for this moment.
When the Seismograph Becomes the Only Inspector
Here is what makes this moment scientifically alarming rather than just politically alarming: verification has now replaced treaty law as the primary check on nuclear behavior, and verification is genuinely hard. On June 22, 2020, a seismic event of magnitude 2.75 registered at 9:18 UTC near Lop Nur, China's nuclear test site. The event was supercritical and yield-producing, according to US Undersecretary of State Thomas DiNanno, who stated publicly on February 6, 2026, that China used decoupling techniques to reduce the detectable signal and evade Comprehensive Nuclear Test Ban Treaty monitoring. Think of decoupling like padding the inside of a drum: the explosion still happens, but you muffle it so the neighbors don't notice. Senator Tom Cotton has stated the CIA assesses both Russia and China have conducted supercritical tests. China denies everything and refuses observers at Lop Nur.
I want to be precise here, because precision matters: the US allegations about the 2020 test are detailed and specific, citing seismic data, site location, and yield range in the hundreds of tons. But I have not seen independent replication of the analysis by a non-governmental seismological body. That gap is not reassuring; it's a methodological red flag that tells us we are operating on intelligence assessments rather than confirmed scientific consensus. The difference between those 2 things is enormous when your next policy step might be resuming nuclear testing.
Trump instructed resumption of nuclear testing "on an equal basis" with China and Russia. Shashank Joshi at The Economist put it plainly: a US resumption could unleash a spiral of global testing. That assessment strikes me as correct. The US last tested in 1992. Returning now would hand every nuclear-armed state, and several aspiring ones, political cover to do the same.
China's Silos Are Not a Deterrent Signal. They Are a Posture Change.
China's ICBM silo count now exceeds US totals. That's not a deterrent force of ~200 warheads kept as a last-resort guarantee; that's a warfighting posture. The construction pace outran FY27 intelligence estimates, meaning the trajectory is accelerating faster than US analysts projected. Japan and South Korea are already questioning the reliability of the US nuclear umbrella. This is what cascading credibility collapse looks like before it becomes a crisis.
Trump's stated goal of a multilateral arms control framework that includes China is actually the right instinct. China's refusal to participate is the obstacle, not the ambition. The fair point to concede is that previous bilateral US-Russia frameworks deliberately excluded China, giving Beijing strategic room to expand without accountability. That exclusion was a genuine error. But the answer to that error is patient diplomatic pressure and verification-first proposals, not resumed testing that would shatter the CTBT framework entirely.
The Arms Control Association briefing on March 24 should produce one concrete deliverable: a proposed verification protocol that China, Russia, and the US could each accept without formal treaty ratification. Seismological monitoring already exists. Satellite transparency measures already exist. Use them as the foundation, build the legal architecture around demonstrated verification capacity, and stop waiting for a successor treaty to materialize from political will that isn't there. The tools for accountability exist. The political agreement to use them is what requires urgent scientific and diplomatic engineering.
