Well like some people have been saying, Trump is a symptom and not the cause.

The reason why we have Trump and far-right movements is because of all the craziness with terrorism and refugees and immigrants, etc. And the reason why we have terrorism, is because the US aided Al-Qaeda back in the days with weapons and finance to provoke Russia, and now the Al-Qaeda has bitten back them in the ass via 9/11. And the reason why they're provoking Russia, is because after the collapse of the USSR, the NATO, which is a kind of a collective military organization of "the West", needed something to do when they no longer had the big, bad enemy of the Soviets.

The US officially has over 800 bases all over the world. This is no doubt a drain on the US economy, not to mention the trillions of dollars already wasted in the wars in Middle East and other places. Trump no doubt sees this as a waste and one of the reasons for the decline of the US economy, even though the military-industrial complex is part of what's fueling the US economy. Nonetheless, he correctly thought that NATO might had something to do with this, so he talked about dismantling NATO or leaving NATO or something. It's not clear how much he meant it or he just said some bullshit that he doesn't believe in to gain votes, but it's obvious that "the Establishment" did not take kindly to him even mentioning leaving NATO or getting along with Russia or something.

The US and the NATO need enemies to keep its machinery going. That's the entire reason why there's this whole craziness with Russiagate.