But there are limits to how hard such policies can be pushed, right? For example the President can't just order the military to shoot all of our missiles straig

But there are limits to how hard such policies can be pushed, right? For example the President can't just order the military to shoot all of our missiles straight up in the air, as many soldiers will balk and even if a few do get launched, the jig will be up. (however it might be part of a good strategy for when you are about to lose hold on power) An explicit policy of this administration is to decrease the value of the US dollar. And while monetary inflation does somewhat influence other countries' willingness to loan money (ie buy Treasuries), isolating us from our allies and demonstrating general instability are also quite fundamental to that.