In Trump's words, any NATO country that spends less than 2.0% of its national Gross Domestic Product on its defense budget. So, if a NATO country spends, say, 1.75% of its GDP on national defense, and is moving toward the 2.0% goal, Trump would "encourage" Russia to "do whatever it wants" to that country. And the US, with Trump as Commander-in-Chief, would probably renege on its NATO mutual defense commitment. Trump has said this more than once. Latvia, Estonia and Lithuania (all NATO countries that border Russia and rely on NATO's mutual defense pledge for their freedom from Russian attack) are shitting bricks over Trump's possible election. New NATO entrant, Finland, is also very concerned about Russia (with whom it shares a very long border). Poland, bordered by both Russia and Belarus, is also very concerned that Trump means what he says. I listen to what Trump says. I take him at his word.
Read up on Kaliningrad and the Suwalki Gap. This is NATO's Achilles Heel regarding Russian aggression against the Baltic countries. The entrance of Finland and Sweden into NATO have given NATO another, and safer, launching ground from which to counter a Russian attack on the Baltic countries. When Finland and Sweden were neutral, defense of the Baltic countries would have required NATO troops traversing Kaliningrad and the Suwalki Gap. Of course, even with Finland and Russia added, NATO resistance against Russian aggression will be unsuccessful if the US reneges on side of the mutual defense treaty (that has kept Europe safe for 80 years).