Before the U.S. went to war, Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, told President Trump that an American attack could prompt Iran to close the Strait of Hormuz.

Caine said in several briefings that U.S. officials had long believed Iran would deploy mines, drones and missiles to close the world’s most vital shipping lane, according to people with knowledge of the discussions.

Trump acknowledged the risk, these people said, but moved forward with the most consequential foreign-policy decision of his two presidencies. He told his team that Tehran would likely capitulate before closing the strait—and even if Iran tried, the U.S. military could handle it.

Now, two weeks into the war, Iran’s leaders have refused to back down, and the Strait of Hormuz has emerged as Tehran’s most potent leverage point.

Iran has blocked tankers from the strait and struck cargo ships, triggering a surge in oil prices and an energy shock rippling around the world. 

The joint U.S.-Israel military operation has killed Iran’s supreme leader, targeted military headquarters and damaged or destroyed more than 90 Iranian vessels.

Yet, the price has been steep. At least 13 Americans have been killed, including six in a crash Thursday of an Air Force refueling plane, making the war in Iran the deadliest military operation of Trump’s two terms. At least 140 Americans have been wounded in the conflict. Roughly 175 people, mostly children, were killed in a strike on a girls’ school in Iran, which a preliminary U.S. investigation found was likely launched by U.S. forces.

The U.S. operation is costing billions of dollars a week. More broadly, the growing risk of a widening and drawn-out war threatens the American economy, raising warnings of stagflation, a quagmire of stagnant growth and high inflation.

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’s trust in Caine was buoyed by the successful U.S. strikes on Iran’s nuclear sites last year and the January raid that captured Venezuela’s leader, Nicolás Maduro.

The White House said Trump understood the risks of launching the war, but was determined to eliminate the national security threat posed by Iran. Before the president approved the operation, he and his advisers discussed options to force the reopening of the strait and use the U.S. Navy to escort tankers through the waterway, the people said.

With the strait nearly closed, the Pentagon is now concerned that any American warships escorting tankers through the strait would be targets.

The possible closure of the strait was one of several scenarios Caine and other advisers outlined for Trump in the run-up to the war. 

Caine provided the president with “a full spectrum of military options, along with precise and thoughtful consideration of the secondary effects, implications and risks associated with each option,” said Joe Holstead, Caine’s spokesman.

Some of Trump’s outside advisers are urging him to find an exit ramp, but the president has no plans to immediately end the war, aides and officials said.

That contrasts with Trump’s public statements that the mission has largely been accomplished. “We’ve won,” he told a crowd in Kentucky on Wednesday.

U.S. military officials said the conflict would likely last a few more weeks, at least.

Trump announced Friday evening that the U.S. bombed military targets on Iran’s Kharg Island, intending to pressure Tehran into reopening the strait. 

The president’s critics say the closure of the strait and the resulting economic turmoil reflect a lack of planning and thoughtful consideration in the weeks before the war.

“They had no plan to address the crisis in the strait,” said Sen. Chris Murphy (D., Conn.), who joined a classified briefing Tuesday with administration officials about the operation. “The fact that these guys didn’t have a plan ahead of time, and a week into the war still didn’t have a plan, was pretty shocking.”

Typically, war preparations include weeks or months of classified deliberations, written planning documents, the airing of dissenting views from diplomats and intelligence officials, and

National Security Council meetings with cabinet members to make the most informed decision.

Only a small group was looped into the preparations for Iran—including Vice President JD Vance, Secretary of State Marco Rubio and Hegseth. That narrowed the advice, information and ideas available to the president, who had to balance the many downsides of an attack.

The small-group arrangement was by design, administration officials said. It allowed Trump to respond quickly to shifting developments and was similar to how the president handled the strikes on three Iranian nuclear sites in June. Another reason was to contain leaks, officials said.

Some senior aides and U.S. diplomats who manage Middle East affairs were told little to nothing about plans for the war. They learned the bombing had started from social media and news reports.

With a majority of Americans in polls opposing the war, Trump and his advisers have been trying to make the case that the conflict won’t drag on like the so-called “forever wars” in Iraq and Afghanistan—a red line for many lawmakers and the president’s MAGA base. 

The White House and the Pentagon have launched an aggressive messaging campaign built around U.S. invincibility, mirroring Trump’s own conviction that American military superiority can overcome and outlast Iran’s retaliation. U.S. government accounts have posted stylized videos of strikes, some interspersed with movie or videogame footage.

At the same time, Trump’s team is privately trying to reassure the president that conservatives aren’t abandoning him. They have provided him with polling data in recent days that they say shows the war is popular with his supporters, people familiar with the matter said.

Some Trump allies who have grown skeptical of the operation have coordinated behind the scenes to schedule appearances on Fox News and other TV networks watched by the president to sound a note of caution and warn against a deeper U.S. commitment.