By “some on the right “ you mean your presidential candidate and most of your party.
Some fringe leftists are isolationists, to be sure. Liberals? No.
Going neocon agro W-style won't improve America's geopolitical status. Maybe he's having trouble coming to terms with China rivaling America's economic power and military projection that vaguely resembles what America did, albeit more flagrantly aggressively.
Would it have been justified for Europe to intervene militarily when the US wrested California and Texas from Mexico? Maybe or maybe not, but it certainly wasn’t the first step in the US taking over the world.
In both of those cases there had been decades of nation wide, protests, insurrections and guerilla movements in favor of creating a sovereign nation to prevent domination by foreign powers, Austria in the case of Italy and France in the wake of napoleon for the minor German states.
In Ukraine there has been a decades of nation wide protests insurrections and guerrilla movements in favor of creating a sovereign Ukrainian nation so that they will no longer be dominated by Russia.
Putin is not garibaldi, he is not unifying a people who have shown they want to be part of some wider national project, he is an imperialist.
Putin obviously has expansionist aims. But regional expansionism is widespread, and rarely something countries on the other side of the world need to be involved with. Kuwait certainly didn’t want to be part of Iraq, but that wasn’t any of our business either. Same for South Korea and south Vietnam.
You avoid mentioning NATO and the reasons Putin views it as a threat, probably because it would undercut your claim that there are no worthwhile parallels to WWII here.