Why will the Baltics be different?
Because they are members of NATO.
If NATO doesn't react to the Russian invasion, it will be clearly and very publicly dead. And that would radically change the power equation in Europe and may e.g. lead to Western Europe rearming itself.
I am not saying that if Putin, say, starts grabbing chunks of Estonia, NATO will necessarily intervene. It might decide to die instead. But the odds are very different from the Ukraine case.
And, of course, NATO's original purpose and whole reason for existence is precisely to contain the Russian/Soviet expansion to the west.
And, of course, NATO's original purpose and whole reason for existence is precisely to contain the Russian/Soviet expansion to the west.
I don't think the reasons for forming NATO in 1949 are, or should be, relevant today. Upholding treaties is a legitimate concern, but what people cared about two generations ago when they formed them isn't.
Some of the comments on the link by James_Miller exactly six months ago provided very specific estimates of how the events might turn out:
James_Miller:
Me:
"Russians intervening militarily" could be anything from posturing to weapon shipments to a surgical strike to a Czechoslovakia-style tank-roll or Afghanistan invasion. My guess that the odds of the latter is below 5%.
A bet between James_Miller and solipsist:
I will bet you $20 U.S. (mine) vs $100 (yours) that Russian tanks will be involved in combat in the Ukraine within 60 days. So in 60 days I will pay you $20 if I lose the bet, but you pay me $100 if I win.
While it is hard to do any meaningful calibration based on a single event, there must be lessons to learn from it. Given that Russian armored columns are said to capture key Ukrainian towns today, the first part of James_Miller's prediction has come true, even if it took 3 times longer than he estimated.
Note that even the most pessimistic person in that conversation (James) was probably too optimistic. My estimate of 5% appears way too low in retrospect, and I would probably bump it to 50% for a similar event in the future.
Now, given that the first prediction came true, how would one reevaluate the odds of the two further escalations he listed? I still feel that there is no way there will be a "conventional battle" between Russia and NATO, but having just been proven wrong makes me doubt my assumptions. If anything, maybe I should give more weight to what James_Miller (or at least Dan Carlin) has to say on the issue. And if I had any skin in the game, I would probably be even more cautious.