To put things into better perspective, warmongering is not a left/right issue: some people think "left=peace, right=war", but that's not how it works at all.
Here in the arguably most war-prone country in the world, the U.S., belligerence, and our habit of stepping in militarily all over the world, is a strictly bipartisan affair. In fact, one could make a pretty good argument that the so-called "left" (i.e., the Democrats, and I'm choking a bit as I type that) are even more eager to be seen as capable of raining bombs on people, so as not to be mistaken for wimps, than their supposedly more bellicose Republican counterparts. Plus notice how the parties have done pretty much a 180° on Russia since the late part of the last century. The Dems, who used to used to defend civil liberties against the Repub's Commie witch-hunts, now hate Vlad much more than them and seem willing to all but risk nuclear war to try to bring him down.
But the main influence, which you don't read about at all in the MSM, has nothing at all to do with right/left politics: it's the unholy alliance between government and the arms industry. That alone is enough to keep this misbegotten, totally unnecessary war going for a very long time.
They are all, as my departed hero Alexander Cockburn called them, "laptop bombardiers".
Regarding Donald Trump, as horrible a president as he was (and a person as well), you could say he was right sometimes in a "stopped clock" way. Two important things: his impulse, not carried through but earnest, to get us out of the nightmare of Afghanistan, and his (ineffective, stupid, chaotic) feelers of peace towards North Korea. I believe in giving credit where credit is due. No, he was no peacenik, but in rare moments he could see the writing on the wall. If only Biden & co. could do the same.