But retracting support is the nuclear option.
Figuratively, because you can probably one do it once, so you better pick a good reason for doing it.
And literally, because small European countries do now have to consider nukes.
A more realistic outcome is that French nukes will be stationed in other European countries. But France is also not willing to give up exclusive control over those nukes, and the next French government could very well be far-right, and thus become as unreliable as the current US government. It’s a difficult situation.
I wouldn't be surprised if it happens on the fact they could share the cost between nations alone for something they've already paid for.
For other countries, the problem remains that if the UK or France government turns far-right, the other countries may quickly be on their own again, just like what they now fear with the US.
An EU-level control over the nukes seems unlikely, as France (and even more the UK) want to retain their sovereignty over that.
It wouldn't be all that surprising to see Poland and Finland doing atmospheric tests in the next few months. Given that Ukraine gave up their weapons for a totally vacuous security guarantee it would make sense for them to build bombs too. 2025 could be the year of global nuclear proliferation.
In fact, while most nuclear powers have dabbled in the idea of 'how could we conceal a nuclear test', it seems that only Israel is capable of doing it. That is an argument from the absence of evidence unfortunately.
Only because the US decided to officially look the other way. See "The Vela incident" which was never publicly attributed, but was almost certainly a joint Israel-South Africa test.
Given the sensitivity of global seismometers, I don't think this is physically possible.
Maybe you could test one on the far side of the moon? :)