If the US need Belgium planes to launch nukes, well, europe is truly fucked anyway.

If the US had the French doctrine i.e. any army moving toward France's strategic assets will be targeted with a "warning" shot (yes, the warning shot is to be nuclear), but it does not, US nuclear force is for retaliation only. It will never be launched from planes in the foreseeable future. Which is more than the operational lifetime of F35.

No, this is bully tactics and frankly i really, really hope that Trump dissolve NATO so Belgium don't have to buy planes that can fly 30% of the time.