Yes. But there are two question:
1) what exactly actions they will deem necessary? It's possible that Estonian neighbors will limit themselves with sending formal protests or something like this, and it seems to me, that the USA won't commit suicide in vain attempt to save Estonian regime. I mean even if the USA launch all-out nuclear attack against Russia, it won't save Tallin's regime.
2) what will they do, if "attacked" Estonia (like modern Georgia) say: "Thank you very much, our dear allies, and now go and f#ck off yourselves, we prefer to lost Narva but keep peace with the Russians", and Lithuania and Latvia cancel their membership in NATO and stop discrimination of ethnic Russians?
And it's not a question, but simple statement: Russia can crush NATO countries both in regional (if the USA are neutral) and large scale war (if the USA are in the game, too). WWIII will be definitely very costly, and we are not going to start it just for nothing, but if you are really asking for - we can easily do it (and we can survive and win), but Europe can't survive an all-out nuclear war. It's overpopulated and overdependent of the trade just to keep its population alive.