But it boils down to:
Ukraine never should have existed as it was created as a pawn for NATO to play with.
and/or
Putin is simply defending against NATO
and/or
Obama/USA/NATO broke the agreement for Ukraine to be neutral/never join NATO (not true: there was no agreement for that; there was a nuclear ban in Ukraine from 1993 that Russia felt meant “no NATO ever” but if it was ever an agreement, it was a gentleman’s agreement and not explicit that I could ever find)
Hm, there’s a few others.
One of them was freedom fighting to rescue Russians trapped in Ukraine against neo-nazis… although that excuse sailed once the invasion left the two areas Putin’s Ukaz stated.
“Putin is just doing what’s best for his people and just wants everyone to lay down their arms’ (that is, surrender)
So that’s a few