The President’s decision on Paris is terrible, in some ways all the more so because it was almost certainly driven not by any strategy or ideological goal but emotion and hurt feelings of the moment. If Angela Merkel hadn’t criticized him after the summit, it might have turned out differently. President Trump is entirely capable of being a policy changeling in cases where his own ego injury and Russia are not in the balance.
The saving grace is that this is part of a larger story, a larger battle that has consumed America for the last six months and in some ways almost the last two years. If the US auto industry had not been saved in 2008-09, it never would have returned. This decision has no such necessary permanency. Everything remains up for grabs. This could be undone in 2 years or six months. And in this case I mean not simply the decision on Paris but who controls the US government itself.
The US is in the midst of an existential battle with itself over what it is and will be. There are many signs that Trump is losing that battle. But the US Presidency is in essence and in most respects by design an elective monarchy. Unless and until Trump definitively loses that fight, he is capable of doing profound damage, much as any malevolent, damaged individual is, but in this case on a vaster scale because of the awesome and now perverted power of the US presidency.
Everything remains up for grabs, in play. Much, though by no means all, of the damage can be undone if Trump and Trumpism loses the big fight.