I have to ask.. what in the world is a "radical centrist" ?

Someone so terrified of having their beliefs challenged that they choose to have none.

They'll be the ones saying that "both sides are equally bad" and think it gives them a moral high ground.

GP specifically mentioned "European radical NATO centrists". They likely think that it's up to Zelensky to stop the war and legitimately can't understand why you don't try to appease people like Putin.