This. There's no global bargaining chip to be gained here: if anything, the rest of the world has now fully realized that American exceptionalism is in rapid decline. Witness, for instance, the global reaction to Trump's decision, which has essentially been "that's nice, we'll stick with the agreement". This looks less like a savvy political move and more like a petulant child lashing out because Germany stated the US can't be completely trusted anymore.

Maybe this will garner some points with his most fervent backers, but that set's growing smaller by the day.

The most charitable spin I can think to put on this is that he made an enormously risky bet on a) the rise of populism in Europe and b) the ability of America to cash in on its supposed position of leadership. Turns out a) failed and b) is worth less than we imagined.