What Putin says about the rationale for the war seems to depend on his level of optimism about its outcome. In the earliest stages, he was talking about Grand Duke Vladimir and how Ukraine didn’t have a right to exist as a separate nation. He then moved to “denazification” and “demilitarization,” which can only mean regime change in the entirety of Ukraine. But when the war started to get away from Putin, he began to insist that it was the Ukrainians, not him, who refused to talk peace on the basis of existing conditions on the ground.
At his press conference a day or two ago, Putin was back talking about “denazification” and “demilitarization” again. That means he’s more confident about winning a total victory. For that, he can thank Trump and the GOP.