I'd say war became hot again way back when with Vietnam, Afghanistan, and Korea. Proxy wars but wars nonetheless. A major war? Perhaps 2022 was the start of it like you said, that tracks. Hopefully not though.
One difference is that Ukraine is an international, cross-border war of conquest - the kind that was outlawed after WWII and hardly happened since. Vietnam and Korea were civil wars where the US sought no territory. Afghanistan had a different motive, but no conquest was desired.
1. Short term: nothing major because it can't at the moment.
2. Long term: build up a military that is a credible military deterrent to the US, probably abandon NATO if the US doesn't, and form alliances with Canada and the UK.
