IMHO Trump is hardly aware of the diplomatic power of Europe. In Europe diplomacy is very advanced, because of the competition between countries. Just look at how they target specific republicans by threatening to raise import taxes in very specific products. I think the leader of congress for one? It looks like Trump is not even aware of the level of diplomacy that Europe uses.

I am Dutch by the way, and live there too. I have never been to the USA, so this is my view at things from far away.