The idea that the U.S. military could quickly bring about a regime change spurred President Trump to attack Iran.
President Trump's decision to attack Iran came after briefings about one of the war's biggest risks: that Tehran could shut the Strait of Hormuz and shake the global economy.
The rapidly expanding war has exposed how the White House was counting on the quick collapse of the Iranian regime, how the planning was confined to a small circle of advisers and how confident Trump was that U.S. military force could contain the fallout.
Before the U.S. and Israel launched the military assault against Iran on Feb. 28, Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, told Trump in multiple briefings that an American attack could prompt Iran to close the Strait of Hormuz, the narrow waterway that carries 20% of the world's oil exports from the Persian Gulf to the rest of the globe.
While he acknowledged that it was a possibility, Trump decided to move ahead with the operation. He believed that Tehran would likely capitulate before it could close the strait or cause significant economic damage. And if it came to it, he told his team, the U.S. military would be able to handle it. On Friday evening, Trump said the U.S. bombed military targets on Iran's Kharg Island, a critical hub for the country's crude oil exports, to pressure Tehran to reopen the strait.
Behind Trump's rationale for war was a deep confidence in the capabilities of the U.S. military to deliver a swift, decisive victory, according to administration officials and others familiar with the matter.
The president often brags about the military and its lethality. And he is especially fond of Caine, whom he often refers to by his nickname, Razin Caine. Despite setbacks, Trump has publicly maintained confidence that the military can execute its mission.
But costs continue to mount. At least 13 American servicemembers have been killed, making the war in Iran the deadliest military operation of Trump's two terms, and more than 1,300 Iranians have been killed, according to the country's envoy to the United Nations. Trump and some advisers were also surprised by the breadth of Iran's retaliation, according to people familiar with the matter, including the wave of missiles and drones launched across the region from Azerbaijan to Oman.
Trump's decision last summer to launch a mission to strike three Iranian nuclear sites, known as Operation Midnight Hammer, convinced him that he could bomb Iran, absorb a brief backlash and then personally dictate the off-ramp, U.S. officials and others familiar with the matter said.
The mission to depose Venezuelan leader Nicolás Maduro in January reinforced in Trump's mind that swift regime change could be managed with a well-executed military operation and by backing a more accommodating successor without triggering wider instability.
But that didn't happen this time. Instead, Iran named hard-liner Mojtaba Khamenei as the new supreme leader after joint U.S.-Israeli strikes killed his father. In a statement this week, the younger Khamenei vowed to keep blocking the Strait of Hormuz. Trump has publicly lamented that the military operation killed Iranian leaders who potentially could have ushered in friendlier relations with the U.S.
Preparations for a major military operation typically involve weeks or months of deliberations, written options papers, dissenting views from officials across different agencies, and meetings with the National Security Council. But according to administration officials, planning for the Iran operation was handled by a much smaller circle.
This included Vice President JD Vance, Secretary of State Marco Rubio and Defense Secretary Pete Hegseth. While this allowed Trump to limit leaks and move quickly as events shifted, it also narrowed the range of advice and dissent that reached the president as he weighed the risks of attacking Iran.
Left unanswered were such questions as how to evacuate U.S. citizens in an escalating conflict -- or ensure the next Iranian leader was friendly with Washington, U.S. officials said.
Trump has said repeatedly that the war might end soon and he has already claimed victory. He is facing pressure from outside advisers to end the conflict quickly, as well as concerns from fellow Republicans facing a tough midterm election climate. Gulf allies have also expressed their frustration with Washington as Iran has attacked oil refineries, hotels and other civilian targets, piercing the narrative that Gulf nations are safe places for business within a turbulent region.
But Trump is "dug in," a senior White House official said, adding the timeline being considered remains four to six weeks. The war entered its third week on Saturday. On Friday, Trump said he would end the war when he feels it "in my bones."