If Trump were still president, he would have pressured Ukraine to declear neutrality. They would have still been enjoying peace now. It's not a secret that Trump detests corrupted Ukraine, detest those bandwagon countries that pay little to NATO. He certainly wouldn't support Ukraine to fight Russia. Trump also understands the danger of trigging a nuclear war.
Link: https://www.nytimes.com/2019/01/14/us/politics/nato-president-trump.amp.html