You may have a point. Setting aside Brett’s curious baiting expedition, some roadblocks stand in the way, primarily, U.S. Law, (created specifically to stop Trump) also there actual ideas drawn up by Trump’s team concerning NATO.Honestly done with the X would never do Y commentary...bc it continually proves to be false. It's a failure of imagination.
Of course, there is precedent. President Carter unilaterally pulled the U.S. out of a defense treaty with Taiwan (talk about unintended consequences), but he didn’t have existing U.S. Code for opponents to carry to SCOTUS. Change might be in the air, but I don’t see the alliance ending anytime soon.