Earlier quoted context omitted.
I think this might be a move to stop a world war (between Russia and NATO/Europe). If U.S. also leaves NATO any time soon - the chances for a world war would decrease greatly.
Yes, the isolationist era that followed World War One clearly calmed the rest of the world, so that the various "expansionist" regimes felt less threatened and just let their neighbors be. History rhymes with itself.
That's exactly why 'expansionist' regimes were ready to start some next war, being eager "to get some extra land" as a result of said war.
The current war is different: this is the war that started not out of appetite towards foreign lands, but, basically, out of primal fear, the fear concerning safety. The West was failing at self-reflection and was completely oblivious about their own actions being treated as crossing a real red line for Russia's safety.
You may scare a wandering bear away, but driving it into a corner is both stupid and fatal.