I wonder if the rest of NATO would allow this.
I imagine he'd "pull us out of NATO" like he "pulled us out of NAFTA". Which is to say he'd slap a new "America First" label on the old organization, take a few weeks off to vacation at a bunch of European golf courses, do a big signing ceremony in front of OAN handi-cams, and yell "I Made America Great Again" into the faces of anyone who thinks this is baby-tier bullshit.
Create a paperwork “penalty box” that allows Trump to feel like he’s won but allow future, more sane Presidents, an easy on-ramp back into full membership.
I think the real end-game is about goosing US military exports. Trump threatens a pull out, on the condition that all the member states boost their domestic military budgets. Then those member states buy more shit from American MIC contractors. The MIC rewards Trump with political capital. And Trump takes kickbacks in the form of club memberships and no-show jobs for his extended family.
My man loves to bluff about taking his ball and going home. And he'll happily sign a big executive order with an oversized sharpee, proclaiming "We Aren't In NATO Anymore!" whether or not we actually left, because it plays well with his base. But the real influence that the US has in NATO is more about Trump extending/denying France or the UK or Finland or whomever with navy and air support to hold business assets in former colonies.
Trump knows that and he knows it offers him immense leverage, given how much these other countries rely on US power projection. So he'll very likely get a new wave of EU militarization at the enrichment of American MIC, because its the only way the other NATO states decouple their reliance on the US for "free" military support.