Trump released Iran's frozen assets, in return for them opening the straight and thereby dropping oil prices before the midterm elections.

Reminder, the reason Trump hated the Obama deal was because he construed it as paying Iran not to develop nuclear weapons. Obama was paying Iran with the money from Iran's frozen assets. Trump's deal gives them that money, and has no nuclear agreement.

He didn't hate the Obama deal, he hated Obama therefore everything he does has to be criticized and torn down. If that deal had Iran paying the US, Trump would have said the color of the money was no good. And his supporters would eat it up.

Rising inflation at home forced Trump's hand.