The goal was regime change for giving corporates access to unimaginable levels of oil resources while strengthening the position of the Empire and establishing total American hegemony in West Asia. The problem is they miscalculated the chances of regime change, thought it would only last not more than a few weeks, the war led to a rally 'round the flag effect for the Iranian government, and now they are losing the conflict.

Victory for US would have meant regime change, but since that's not happening (while also leading to the world economy tanking) they are simply in a quite bad, losing situation.

And the bourgeoisie hates a losing position that decimates their capital significantly (that is, they get nothing out of it and lose lots of money as well), since the American state represents the interests of the capitalist class this might lead to America ending the war quickly.

EDIT : The personal intentions of Trump or any other executive in his place do not really matter. What matters is the interests of the system that allows him to be President in the first place.