Trump was once wary of ordering regime change in Iran. Here's what made him change his mind

Saturday’s military operation against Iran shows the dramatic evolution in risk tolerance that President Donald Trump has made in a matter of months. It was only last June that Trump had drawn a bright red line in rejecting an Israeli proposal to target Ayatollah Ali Khamenei. At Israel’s urging during its 12-day war with Iran, Trump had agreed to deploy B-2 bombers to pummel three key Iranian nuclear sites, but worried that killing the cleric could destabilize the region. With Saturday’s strikes, those guardrails were tossed aside. Trump triumphantly announced the Ayatollah's death, part of a battle plan that he and Israeli Prime Minister Benjamin Netanyahu had greenlit.