Which begs the question, why didn't Germany collaborate with France on nukes where they could be a more or less equal partner, compared to the US where they would always be the subservient party with little to no control?
De Gaulle wanted sovereign control of any French nuclear deterrent and did not trust that, if it came to it, the US would put itself on the line for Europe: https://www.nato.int/cps/en/natohq/opinions_139272.htm - presumably, for similar reasons he did not want any dependence on allies, even ones closer in location and likely part of the same conflict.
The US did actually help the French nuclear programme once it started going, under the reasoning that multiple nuclear-armed NATO members is better than one.