Nato was founded to keep the Russians out, the Americans in, and the Germans down. Well, the Germans have figured out how to keep themselves down with their migrant policies. Russia has meddled in the region, but we have too. Look at how Wesley Clark almost sparked open warfare with Russia during the Kosovo campaign. That is what Trump is talking about - pushing Nato into areas that are of no strategic importance in such a way that could spark a much larger war.
The EU has tried/is trying to unseat an American president.
What the heck more do we need to know.
NATO isn’t an alliance any more. It’s a cabal.