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:
- The odds of Russian intervening militarily = 40%.
- The odds of the Russians losing the conventional battle (perhaps because of NATO intervention) conditional on them entering = 30%.
- The odds of the Russians resorting to nuclear weapons conditional on them losing the conventional battle = 20%.
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.
But perhaps it really is always 1939. Or, to be even more glib, what you are saying sounds to me much like:
OK, let's be serious. Let's say that "being Hitler" means going on an ever-increasing campaign of conquest against neighbouring countries that results in a very damaging war. We could note that this kind of behaviour was very common prior to the Napoleonic Wars (Napoleon, Frederick the Great, Charles XII, Louis XIV, Wallenstein, Philip II, Suleiman I, etc etc). Since the Napoleonic Wars, there have been a number of international frameworks more-or-less explicitly devoted to prevent "Hitlers," and which have had some success. However, IR is basically anarchy, which means that when actors fail to abide by the rules of those international framework, forcing them in line means war.
There haven't been a lot of "Hitlers" in recent years. But at least part of the reason that the people you call "warmongers" nipped the likes of Saddam, Milosevic, Galtieri, etc in the bud. For example, Saddam was definitely on the Hitler path in 1991, and what stopped him was western military intervention. And not only did this intervention stop him, but it acted as a warning to other leaders who might be considering more bellicose action, and helped reinforce the rules and norms of our peaceful international framework.
But this commitment is forever being tested, because leaders get glory through war. Consider that the fame and popularity of American Presidents has been shown to be higher the more Americans who die in military combat in their term in office (!) and then multiply that for more bellicose societies such as Russia. A peaceful world requires constant vigilance.
In the current case, it's clear that Putin is engaged in an aggressive campaign of conquest against his neighbours (not merely in Ukraine). It's not clear where this will stop. It's clear that every victory strengthens Putin's domestic position and emboldens him for the next step. This is the classic "Hitlerian" path, and everyone from Hillary Clinton to Prince Charles has noted it. That doesn't mean the West should necessarily intervene (maybe the costs are greater than the benefits) but it's pretty obvious why the comparison is so widely made. I'd say the 'routine' that no-one is falling for is the Panglossian one that Putin isn't a predator - with each new Russian outrage, it becomes harder and harder to sustain.
I haven't heard the (potential) interventions against Qaddafi and Assad justified on the same grounds. There, the justification is usually a combination of (1) humanitarian and (2) preventing failed states, which is rather different.
But you also have to remember that there is not the history between the US and these other regimes the way it is between the US and Russia. Putin is an old communist and he remembers the old days, he remembers them very well and he wants them back. Putin and his cronies chafed in the 90's under Pax Americana and now they have their chance to shake up the international order rather than conform to the American lead way of doing things and I think he is of the opinion that if it doesn't happen now there won't be another chance for a generation.