ISTANBUL

The US Defense Department and National Security Council underestimated Iran’s willingness to close the critical Strait of Hormuz -- through which about 20% of the world’s oil supply normally transits -- in response to US and Israeli military strikes, and the Trump administration brushed aside warnings, according to US media reports.

US national security officials did not sufficiently factor into their planning a “worst-case scenario” in which Iran would block the strategic waterway after the attacks, said a report by CNN citing unnamed American officials familiar with the matter.

Senior officials acknowledged during briefings to members of Congress that the possibility of the strait being closed had not been fully planned for in advance.

According to the sources, the administration believed that shutting the strait would inflict greater economic damage on Iran than on the US, a view reinforced by Iran’s decision not to carry out similar threats following US strikes on Iranian nuclear facilities last June.

The sources also said the Trump administration relied heavily on a small circle of advisers during the planning of the operation, which limited broader interagency debate over the economic consequences if Iran responded by shutting the strait.

“I can’t say that we anticipated necessarily that’s exactly how they would react (by closing Hormuz), but we knew it was a possibility,” Hegseth told a Pentagon news conference, as quoted by The New York Times. “I think it was a demonstration of the desperation of the regime.”

Some military advisers did warn beforehand that Iran could launch an aggressive campaign in response to US-Israel attacks, the Times reported, adding that other advisers were confident that killing Iran’s senior leadership would open the way for “pragmatic” leaders who would end the war.

Officials from the Treasury and Energy departments were present at some planning meetings before the operation began, but their agencies’ economic forecasts and analysis were given less prominence than in previous administrations, said CNN.

When told of risks that war could push up oil prices, US President Donald Trump “downplayed” the possibility, saying crippling the Iranian regime was more important, the Times said.

Global oil markets have been highly volatile in recent weeks amid concerns about supply disruptions following the escalation of the Iran conflict. International benchmark Brent crude has surged toward the $100 per barrel level as traders assess the potential impact of tensions around the Strait of Hormuz, a key shipping route for roughly one-fifth of global oil supplies.

Since Israel and the US launched joint attacks on Iran on Feb. 28, so far killing some 1,300 people, including then-Supreme Leader Ayatollah Ali Khamenei, hostilities have escalated.

Iran has retaliated with drone and missile strikes targeting Israel, Jordan, Iraq, and Gulf countries hosting US military assets.

Iran has effectively closed the Strait of Hormuz since around March 1.