Though NATO is also guilty of overreach, one of the triggers in the Ukraine was the move to join the EU and the threat it might join NATO. The Russians would prefer the countries of the former Yugoslavia stay neutral given their proximity to the Black Sea.
Finland has managed to stay independent by combining two elements, a commitment to self--defense that makes it clear to the Russians that conquest would be costly, messy and not worth the trouble, and careful diplomacy and actions that avoid any threat to Russian interests. In one sense Trump is doing the Baltic states a favor by removing dependence on NATO and the realization that more important than a NATO trip wire is preparation for bloody resistance that will make invasion politically untenable. But also acknowledgement that they will always be in the Russian sphere of influence and that overt opposition is probably not the best policy.
If the Ukrainians really wanted to screw the Russians, they'd hold a UN sponsored referendum in the East with two options, stay in the Ukraine or join Russia - and the last thing the Russians want are the Eastern, Russian speaking provinces to join Russia, because this is the poor, run down industrial section of the country, akin to the West Germans absorbing East Germany, except the Russians can't afford this, and also can't afford to be seen rejecting Russian speakers. The Crimea was a different matter, Russia was never going to relinquish control, it's too strategically important to them with a major naval base that allows control of the Black Sea and entrance into the Mediterranean (But through the Straits of the Dardanelles, under Turkish control). The Ukrainian government should have offered a 100 year lease, thus establishing ownership of mineral rights in the Black Sea while reassuring the Russians that they could maintain control.
The point is that dealing with the Russians, going back to Czarist days, requires a good sense of the balance of power, making it too costly for the Bear to flex his claws, but without trying to provoke the Bear into doing something stupid out of anger or fear. Unfortunately, the West got intoxicated by success with the fall of the Soviet Union and forgot history.
This is the same situation the countries of Southeast Asia face with China, Vietnam bloodied the Chinese nose a couple decades ago, but is still careful not to challenge Chinese hegemony directly.
We cannot afford the cost of being the counterweight to Russia and China, rather, we need these alliances because they lower the cost to us of maintaining the balance of power, we can provide air power for Southeast Asian countries while limiting our direct engagement, the same should be true in NATO. What we need to avoid are Vietnams and Afghanistans, open ended conflict with no resolution that is favorable for us, draining our treasury and the blood of our young soldiers.
The world is too dangerous to disengage, and too costly to rule, at best, we can manage things by "talking softly and carrying a big stick."
Unfortunately, the current President has a big mouth and small hands.