The only thing that could trigger an all out war - maybe nuclear - would be the event in which the Russian Federation begins to capture european territories, ef

The only thing that could trigger an all out war - maybe nuclear - would be the event in which the Russian Federation begins to capture european territories, effectively becaming an empire (again), but more important, potentially starting to restrict US from most of the natural resources out of the american continent. It is not quite extreme to imagine they'll fortify the Mid East as fast as they can (they've already started, most of those countries are full loaded of advanced weaponry right now, you may wonder to fight against who), then they'd begin to build up military strengh in north of Africa, now you are in the XXII century, and they'll probably be replaying the Marshall strategy to capture african nation-state of interest, in order to contain the new russian borders. All in all, the future will have no more than 3 super powers, ironically quite similar to what Orwell predicted in his book. 1984 I do not see this suddenly happening, but in a few decades you could be seeing this happening. Not that the West isn't aware of this or similar hypothesis, hence you've got all those billions being poured into Ukraine right now.