The US has always been at the helm of NATO. The US Empire is the reason NATO exists, the EU is thoroughly vassalized and subservient to the US. If the US was kicked out of NATO (lol), NATO would crumble, and the EU would be forced to either trade more with Russia or China to make up for the utter loss of their position in the western imperial system. The EU cannot stand on its own, it depends on imperialism, and currently relies on the US sphere of influence to perpetuate itself.