> Because, IMO, Russia would be destroyed the first time they threatened NATO.
Maybe. Or maybe the big powers might realize that sending hundreds of thousands or even millions of people to die in an all out war (depending on how big it gets and who else gets involved) is a harder sell than settling on appeasement and so smaller states would lose their sovereignty.
I live in Latvia. If there's no risk of MAD, then what's to prevent some opportunistic Russians from invading my country and seeing whether NATO would actually do something about Article 5? Some are pondering whether that's not a direction that Russia could move in even now - stage something relatively small and see how NATO responds. They're already regularly violating our airspace and doing cyber warfare against us and trying to drum up opposition to our government (as flawed as it may be) by the ethnic Russian people.
Could go either way.