With Friends Like Trump... What's Europe's Answer to 'America First'?

It's Donald versus Donald. The president of the European Council let loose on trade tariffs and the Iran nuclear deal ahead of an EU leaders' dinner in the Bulgarian capital on Wednesday. A fighting speech, but how does it help those trying to salvage the Iran deal? Already French giant Total has warned its new mega gas project with the Iranians is in jeopardy. How can the EU respond when the US owns the currency used to trade oil? What will Europe do?