The Russian regime is an autocracy, it is evil. It might not appear very different from good regimes like ours. But even evil regimes can enter NATO. At the very least NATO countries are not going to invade other NATO countries. We know that much; and we know that's as good a defense against WWIII ever starting as we have for available options.
I myself recommend we America restart and resume a peaceful, bilateral annexation campaign with the multi-generational goal of bringing the whole world under the control of our Constitution, which will end the threat of WWIII permanently in the nuclear age.
North Korea? Iran? Russia? China? We want them all to be Americans. Then there will be no more WWIII threat, and all nuclear weapons will be under the control of the Constitution.
But in the meantime, we know that one NATO country will not invade another NATO country. This is a pretty good idea in international relations in the nuclear age. How else can you reliably get other people /countries who have nuclear bombs to only ever use them the right way?