International politics ain't that easy.
~~Many people in Europe still admire Trump. IIRC Trump has higher support in the EU, than in the US.~~
In my country (Poland) directly fighting against the US is political suicide.
Edit: I were wrong, Trump approval rate in the EU is around 20%, compared to 30-40% in the US.
Still, international politics isn't quite as easy as people make it to be.
So you gambled on them?