De Gaulle's argument is faulty. It is in Europe interest that any war remain conventional, i.e. not escalate to nuclear warfare. A direct deduction from this is that any extended umbrella should -- unlike the US and British in NATO -- NOT, repeat, NOT, include option for such escalation.

Indeed, the ONLY credible nuclear threat is retaliation-in-kind; first-use threats lack credibility as we now see (or ought to see) with Putin's sabre rattling. Unfortunately, NATO cannot call his bluff, because it is in the same delusional business itself, and has come to view the commitment to resort to nuclear arms as the "glue" of the alliance. (See my piece: https://medium.com/@aaron-tovish/liberation-day-minus-7715-log-9-theyre-all-bluffing-not-just-putin-but-that-doesn-t-make-it-ok-78d929273df9 )

Don't hold your breath waiting for Trump to expose the folly of first-use options; but maybe -- just maybe -- Macron and company will renounce them.