Could we drop the in-fighting here and concentrate on what OP asked?
Trump is a business man withe folie de grandeur and apparently believes he can do no wrong. Whether Vance also believes Trump can do no wrong, or is only doing as he is told is not something I can express an opinion on.
It looks as if the pair of them think they can solve the entire problem caused by Putin's war with Ukraine without the considering what Ukraine wants or needs, and without listening to the opinions of the political leaders of the countries a great deal nearer Ukraine and Russia (all of us) than the USA.
Unfortunately, since the end of World War II, Europe and Great Britain have encouraged the USA to consider itself the leader of the free world, so right now the present generation of politicians in Europe are dealing with the whirlwind their parents' generation sowed.
The only faint glimmer of light I can see is, that by standing up to Trump, as Zelinsky, Macron and Ursula von der Leyden are doing seems to be inducing him to pipe down a little. Which goes to show that the man is a bully and can be dealt with, if we are prepared to make ourselves unpleasant enough, as all bullies can.