President Trump and Prime Minister Netanyahu pose the first credible existential threat to the Iranian regime since 1979. Although the U.S. and Israeli strikes on Iranian military and nuclear targets degraded Iran’s military capacity, there is no indication that the regime is significantly more likely to fall as a result. A similar plan would have a significant chance of toppling the Iranian regime within months. The Iranian regime has proven that diplomacy cannot resolve threats to U.S. national security. Averting an Iranian nuclear cataclysm largely depends on adopting a proven ground strategy, led by pro-Western Iranian forces in conjunction with U.S. military support.