What he is doing is undermining the EU. The EU was designed to take many countries and combine their economies to create one economy bigger than Americas to trade with China. Why? To undermine America's leverage and influence on the world. Our economy is so large it dictates the world economy. So our "allies" in Europe got in bed with China to create the EU. The EU is now china's biggest customer, not America. They supply the EU with everything. Not by much though. It takes every one of those EU countries working together to exceed our economies size and they are just barely bigger than ours now. This is why BREXIT is such a huge deal to the EU. If Britain pulls out completely then the purpose of the EU fails. With them removed América is back to having the largest economy and dictating global economy basically single handedly. Which means our thumb back on top of China again. The whole point of the EU was to undermine and shrink the US economy to unseat us as a super power. Trump is making moves to completely get Britain out of the EU. He's using trade because that's the EU's biggest weapon. They try to control what goods you are allowed to have and not have in your country as rewards and punishment. If Trump can get Britain completely off the EU's tit then the EU fails and other countries leave it as it no longer has the economy size to dictate policy in the world. Making it a failure and a failed experiment. Toppling the EU starts with Britain getting free of it.