America is in decline. China is rising. War may be inevitable in the end but nuclear strike between superpowers is unlikely and I would hope - never happens. I think Putin is 'mad' enough to use tactical nukes - determined to hold/annex parts of Ukraine possibly at all costs - which would mean tactical nukes. His thinking is that using 1 or 2 would force Ukraine to surrender/negotiate annexures. No country will launch nukes into Russia as a counter so it is possible this happens. Only real solution is that his own people remove him - unlikely, but the possibility grows as he forces his countrymen to fight. More likely that as unrest grows at home, he chooses the nuke option. I hope I am wrong.