In each of those times we successfully avoided nuclear war.
I dunno, Putin is still saying he'll totally start a nuclear war. Postponing it while giving him time to grow stronger (regardless of whether he squandered it) doesn't seem to have worked out so far.
There is no surviving a nuclear war, how strong (or weak) he grows is irrelevant when just 10% of Russia's nuclear arsenal could render the planet uninhabitable. Letting him take chunks out of his neighbors is a very easy price to pay for not dying in WWIII. He knows this, which is why it's his strategy to just do a bit at a time. If he were truly an unstable madman, he'd be invading all of his neighbors simultaneously while egging NATO. The fact that he has never done that is a great indicator that he hasn't completely lost his sanity just yet.
Maybe I'm wrong but I just don't think that giving up chunks of territory to anyone threatening nuclear war is a great foreign policy.
Why? At what point do you say "I'm willing to gamble the entire planet's habitability on this piece of land"? A lot of these arguments sound more like a desire to not "let Putin win" or some other egotistical gibberish versus the actual stakes at hand here. I would let Putin take all of non-nuclear Europe before I gamble a single American getting wiped by a Russian nuke. If Russia nukes us, we have to nuke them back, then the entire planet loses. Yes, the whole planet. A worldwide extinction event that humanity may not survive (and if it does, we lose several thousand years of civilizational progress over the course of a few days).
It doesn't make sense to risk nuclear war over some muddy terrain in Eastern Europe. Quite literally anything we do to Russia ratchets up the chance they end the world. It would be the irrational choice, yes, but massive wars have started over irrational choices that were easily avoided.