I think its surprising how short the memory can be for this stuff. Look how long passed between the British invading America and burning down our capital (1812) and us fighting on the same side in the Great War (1917): not even 4 generations. There are obviously counterexamples, but it's not a slam dunk that 10-ish years of Trumpism will sour the European memory on America forever. Maybe it will, maybe it wont. I would think material facts we don't know yet will be the biggest determining factor here, rather than the other way around.