By Phil Stewart and Idrees Ali
WASHINGTON, Feb 28 (Reuters) - Ahead of the U.S. attack on Iran, President Donald Trump received briefings that not only delivered blunt assessments about the risk of major U.S. casualties but also touted the prospect of a generational shift in the Middle East in favor of U.S. interests, a U.S. official told Reuters.
The launch of what the Pentagon called "Operation Epic Fury" on Saturday plunged the Middle East into a new and unpredictable conflict. The U.S. and Israeli
militaries struck sites across Iran, triggering retaliatory Iranian attacks against Israel and nearby Gulf Arab countries.
The official, who spoke on condition of anonymity, said the briefers described the operation to the president as a high-risk, high-reward scenario.
Trump himself appeared to echo that sentiment when he acknowledged the stakes at the onset of the operation, saying "the lives of courageous American heroes may be lost."
"But we're doing this not for now, we're doing this for the future, and it is a noble mission," Trump said in a video address announcing the start of major combat operations.
"For 47 years, the Iranian regime has chanted death to America and waged an unending campaign of bloodshed and mass murder ... We're not gonna put up with it any longer."
The briefings from Trump's national security team help explain how the president decided to pursue arguably the riskiest U.S. military operation since the invasion of Iraq in 2003.
Ahead of the strikes, Trump received multiple briefings from officials including CIA Director John Ratcliffe, U.S. General Dan Caine, the chairman of the Joint Chiefs of Staff, U.S. Secretary of State Marco Rubio and Defense Secretary Pete Hegseth.
On Thursday, Admiral Brad Cooper, who leads U.S. forces in the Middle East as the head of Central Command, flew to Washington to join discussions in the White House Situation Room.
A second U.S. official said that prior to the strikes, the White House had been briefed on a number of risks associated with operations against Iran, including retaliatory strikes on multiple U.S. bases in the region by Iranian missiles that could overwhelm defenses, as well as Iranian proxies attacking U.S. troops in Iraq and Syria.
The official said that despite the massive military buildup by the United States, there were limits to the air defense systems that had been rushed into the region.
Experts caution that the unfolding conflict could take dangerous turns and the first official said the Pentagon's planning did not appear to guarantee the outcome of any conflict.
Trump called on Iranians to topple the government but that is easier said than done, said Nicole Grajewski with the Carnegie Endowment for International Peace.
"The Iranian opposition is pretty fragmented. It's unclear what the population is willing to do in terms of rising up," Grajewski said.
Both U.S. officials requested anonymity due to the sensitivity of the internal discussions.
The White House did not immediately respond to requests for comment. The Pentagon declined to comment.
TRUMP'S SWEEPING GOALS
In the weeks leading up to the attack, Trump ordered a major military buildup in the Middle East. Reuters reported military planning to carry out a sustained campaign against Iran, if that is what the president chose. Plans included targeting individual officials, officials said.
An Israeli official said Iran's Supreme Leader Ayatollah Ali Khamenei and President Masoud Pezeshkian were both targeted but the result of the strikes was not clear.
Trump made clear on Saturday that his objectives in Iran were sweeping, saying he would end the threat posed by Tehran to the United States and give Iranians a chance to topple their rulers. To accomplish this, he outlined plans to lay waste to much of Iran's military as well as deny it the ability to build a nuclear weapon. Iran denies seeking a nuclear weapon.
"We are going to destroy their missiles and raze their missile industry to the ground... We're going to annihilate their navy," he said. "We're going to ensure that the region's terrorist proxies can no longer destabilize the region or the world and attack our forces."
Trump's decision demonstrates an increasing risk appetite, far greater than when he ordered U.S. special operations forces into Venezuela last month to seize that country's president in an audacious raid.
The unfolding campaign against Iran is also riskier than when Trump ordered U.S. forces to bomb Iran's nuclear sites in June.
Iran's Revolutionary Guards threatened all U.S. bases and interests in the region and said Iran's retaliation would continue until "the enemy is decisively defeated."
Experts warn that Iran has many options for retaliation, including missile strikes but also drones and cyber warfare.
Daniel Shapiro, a former senior Pentagon official for Middle East issues, said that despite the U.S. and Israeli strikes, Tehran would still be capable of causing some pain.
"Iran has many more ballistic missiles that can reach U.S. bases than the U.S. has interceptors ... some Iranian weapons will get through," said Shapiro, also a former U.S. ambassador to Israel. "(The strikes are) a major gamble."
(Reporting by Phil Stewart and Idrees Ali; Editing by Don Durfee and Daniel Wallis)
