The idea that Germany will ignite nuclear war with France if we pull out, or Japan will ignite nuclear war against Russia, China, or the US... Is frankly absurd. And not just because it would be suicidal... The vast majority of modern Germans, I can say with absolute certainty from much experience, are absolutely ashamed of their history and would never support repeating it. I think this is less true in Japan, but I don't have the same experience to know. Either way, their constitution prevents them from having a military, and they have proven for a long time to be trustworthy allies. As have all our European partners, by the way.
Modern culture in the west and beyond is completely anti-expansionist wars, hence the response to Russian actions. That isn't going to change over night.