During the Cold War, even at times of greatest nuclear tension, Washington and Moscow maintained an unwritten rule: if a test was carried out, the world had to know about it. The explosions were political signals as much as military experiments, designed to be seen, measured and, of course, feared. Therefore, talking about detonations so small that they barely leave a seismic trace and about tests designed not to be detected, generates great concern.
The United States just accused China of exactly that.
An unprecedented accusation. It happened last Friday, when the United States denounced China for having carried out at least one explosive-yield nuclear test in 2020 and preparing for other low-yield ones, a complaint made in Geneva through Undersecretary Thomas DiNanno just as the classic arms control framework is collapsing after the expiration of New START.
According to Washington, Beijing would have resorted to decoupling techniques to dampen seismic signals and hide underground detonations, an accusation of enormous political significance because it breaks the previous ambiguity and indicates for the first time a specific date, June 22, 2020, in the middle of the debate on whether the United States should recover the option of testing nuclear weapons again.
The diffuse limit. The technical and legal background is key to understanding the controversy, as both China and the United States have signed but not ratified the Comprehensive Nuclear Test Ban Treaty, which allows subcritical tests without a self-sustaining nuclear reaction but prohibits any explosion with measurable yield.
Washington maintains that Beijing would have crossed that line with very low-power tests, difficult to detect, while the body in charge of verification, the Comprehensive Nuclear Test Ban Treaty Organization, assures that its network did not detect any event compatible with a nuclear explosion that day, thus underlining the fragility of a control system that never came into full force.
Lop Nur, satellites and silent expansion. We have told it other times. American suspicions are also supported by satellite images and intelligence analysis that point to intense activity in the historic Lop Nur industrial site, with new excavations, tunnels and drilling that could serve both for subcritical tests and for higher-yield detonations.
This movement fits with the rapid expansion of the Chinese arsenal, which would already exceed 600 nuclear warheads and could reach a thousand before 2030, reinforcing the perception in Washington that the real strategic challenge is no longer Moscow but rather a Beijing with the capacity and will to challenge US military primacy.
A new nuclear race scenario. Washington’s denunciation comes accompanied by a clear political message: without binding limits, transparency or verification mechanisms that include China, the system inherited from the Cold War ceases to serve, and the United States reserves the right to take “parallel steps,” including the resumption of tests, if it considers that other actors are breaking the rules.
Beijing vigorously rejects the accusations, vindicates its moratorium and its no-first-use doctrine, but the simple verbal clash shows a change of phase, one with the risk that the end of New START and mutual distrust will open the door to a new nuclear race in which small, almost invisible explosions can have enormous strategic consequences.
Image | CCTV
In WorldOfSoftware | Nuclear fusion is humanity’s great utopia in the short term: China has already set a date for it
In WorldOfSoftware | China is building something that looks like an oil well. It is actually a nuclear bunker with a command center
