You are writing as if Putin is a rational actor. That presumption could not be more wrong. Russia invading Ukraine is already so illogically asinine that nobody should claim to have even the slightest idea what Putin will actually do in the future. He is chaos.

NATO receives no benefit by standing by and letting Ukraine fall. The next fight would be on NATO soil, against a battle hardened, victory spirited aggressor. Oh, and he would know for a fact his nuclear threat worked like a charm.

Now is the time to stop Russia’s aggression once and for all, nuclear threat or not. Putin has never gotten less crazy. There is zero reason to assume a Ukrainian victory would pacify him. We will win handily against any future conflict. But why choose a harder victory tomorrow with one less ally, when we could have lasting victory today?