I've been thinking a bit on how to prevent Putin from pulling the same sort of shenanigans with the Baltic NATO states.
My earlier suggestions on other threads for a "strong NATO military buildup" ran into vague objections that I think were based on a fear of returning to Cold War tensions, so I thought I'd come up with an alternative idea.
It occurs to me that Putin always justifies these invasions based on the notion of protecting ethnic Russians.
We could do a lot to undermine any Russian justifications for messing with Estonia/Latvia/Lithuania simply by ensuring that the Russian minority in these countries have strong protections for their civil rights.
Unfortunately I see a downside: it might send the wrong message. Civil rights protections are of course always a good thing, but this might project an image of appeasement, and right when our allies are looking for reassurance of strength.
However, it might be possible to combine this with my former idea. We could tie an offer for increased military presence with a requirement that a state have strong civil rights protections for minorities. That would blunt the image of appeasement. And the civil rights protections would help mitigate any tensions with Russia that might result from our increased troop presence.