yes and Ukraine would never be considered the aggressors. I have never claimed them to be aggressors nor warmongers.
us joining the war is an escalation, which is an act of aggression. supporting that aggressive act of joining a war that doesn't involve us is warmongering. it doesn't matter if Ukraine can or can not defend themselves on their own. that is a completely arbitrary point to the discussion. another nation joining in would still be an act of aggression towards Russia. thus warmongering.
Japan attacked Pearl Harbor. We declare war against Japan in a defensive act. Germany then declares war on the US coming to the aid of Japan, making Germany the aggressors in our war against them too.
you didn't address the Chinese in the Korean war. they were clearly aggressors despite joining the defense of another nation. why? because they weren't part of the war, they joined it. making them the aggressors. and the support of that aggression would make them warmongers.
Desert Storm, the US was 100% aggressors. even though we came to free Kuwait.
if you are so found of definitions you need to go look up aggression since your definition uses that phrase. "the action or an act of
attacking without provocation." we have not been provoked.