Compare with this statement made in 1938:
Hitler has started by annexing Germanophones, but I think he is unlikely to then go for a full scale conquest of all Europe.
Should Germany attack a country formally allied with the major powers of France and Britain, like Czechoslovakia, it would at the very least be financially crippled by loss of trade with Western European countries, the conflict would likely excalate to a full scale conventional war with the US. Hitler may not be exactly a nice guy, but in 1938 he certainly doesn't seem crazy.
Also, even if he was crazy, Germany, while not being exactly a paragon of democracy, is not a dictatorship. The people who keep him in power would depose him if they saw him as a threat to their material interests and safety.
Parts of Czechoslovakia and Poland were parts of what had been Germany and populated by German-speaking people. Britain (and later the US) declared war on Germany, not the other way around; my understanding is that Germany at that time did not want war with Britain and had not expected the declaration.
Given Hitler's views on the slavic peoples, Nazi Germany was always going to go to war with the USSR and Yugoslavia sooner or later, but I don't find it implausible that Western Europe (and the US) could have stayed out of that war, had that been how we wanted to play it.
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.