They don't need to do full nuclear detonation.

A subcritical nuclear test is an experiment that uses high explosives to compress fissile material like plutonium without reaching a self-sustaining nuclear chain reaction, resulting in no nuclear explosion. These tests are performed to study the behavior of nuclear materials, answer questions about weapons design and safety, and provide data for computer simulations used to maintain the safety and reliability of a nuclear arsenal. The United States conducts these tests because they are not considered nuclear tests and are therefore not prohibited by the Comprehensive Nuclear Test Ban Treaty (CTBT).

Trumps announcement is a response to Russia having tested their new Poseidon and Burevestnik missiles, but they didn't detonate any nuclear weapons, they just tested the nuclear propulsion system.

Russia’s Burevestnik and Poseidon tests
http://www.iiss.org/online-analysis/missile-dialogue-initiative/2025/11/russias-burevestnik-and-poseidon-tests/

How fortunate are we that only "sensible" fellas have their fingers on the nuclear button, Trump, Putin, Xi, Kim, Netanyahu, some fruit loop in Iran etc etc. Yes, we can all sleep soundly in the knowledge that only sensible fellas have their fingers on the nuclear buttons. Oh! what is that bright light, and loud rumbling coming my way? Oh no! one of the sensible fellas finger slipped! Oh well, bye-bye human race, see ya in the next universe!

Bonger 1405.

I think it’s only a storm, ( maybe in a tea cup), take it easy, go back to bed now. A false alarm.

Nuremberg Dan,

You sent that same report from Hiroshima 6th August 1945. I understand if you man Adolf had the bomb, I wouldn't be typing this!