U.S. negotiations with Iran aimed at curbing Tehran’s nuclear program were widely seen as an important way to preserve regional peace. They ended up being the perfect cover for a surprise Israeli attack.

With a sixth round of talks between Trump administration envoy Steve Witkoff and his Iranian counterparts set for Sunday in Oman, Israeli and U.S. officials warned of military action if Iran didn’t agree to end its production of fissile material that can be used in nuclear weapons.

Instead, Israel hit first, achieving tactical surprise for a devastating series of blows that killed three top Iranian generals and key nuclear scientists and hit sites linked to the country’s nuclear programs.

On Friday morning, President Trump, in a social-media post, wrote, “I gave Iran a chance to make a deal” but “they just couldn’t get it done.” He said the Israeli strikes were carried out because of Tehran’s intransigence and urged the Iranians to reach a deal “before there is nothing left.”

On Thursday, Trump said he didn’t think an Israeli attack was imminent, “but it is something that could very well happen.” He also said Washington and Tehran were “fairly close to a pretty good agreement” but that Iran would need to make further compromises to avoid conflict.

Hours later, Israel launched hundreds of warplanes in several waves to hit targets across Iran.

“There is no question that the Witkoff mission was a major contributor to the surprise,” said Dennis Ross, who served as a senior official on Middle East issues during Democratic and Republican administrations. “The Iranians would have assumed that Israel would not attack while the talks were under way and a meeting was about to take place.”

Israeli Prime Minister Benjamin Netanyahu had raised possible attacks on Iran in a call with Trump on Monday, two U.S. officials said. Soon after, the U.S. began moving some diplomats and military dependents out of the Middle East. Trump administration officials told The Wall Street Journal on Thursday that Israel was prepared to strike Iran within days.

Trump administration officials insisted Thursday night that Witkoff was still planning to attend the Sunday talks. But the possibility of a meeting with his Iranian interlocutor appeared uncertain with Tehran vowing to retaliate against Israel and some hard-line Iranian officials accusing Washington of being complicit in the Israeli attack.

U.S. officials didn’t respond Thursday night to questions about when the White House first learned that Israel intended to strike before Witkoff’s Sunday meeting in Oman.

Secretary of State Marco Rubio said in a statement that the U.S. wasn’t involved in Israel’s strike. But he didn’t rule out a U.S. role in helping Israel defend itself against Tehran’s retaliation, a scenario that could draw Washington into the conflict and impel the Pentagon to rush more forces to the Middle East.

The possibility that Israel might take military action against Iran has long been a concern for U.S. administrations, which shared the Israelis’ anxieties about Iran’s growing nuclear efforts and the potential that they might eventually enable Tehran to field a nuclear weapon.

A major worry was that Israel’s airstrikes could damage but not destroy Iran’s nuclear program because much of it was buried and dispersed. That might allow Iran to continue its nuclear program covertly. Another longstanding fear was that Iran might respond to an Israeli strike by lashing out at U.S. bases in the region, Washington’s Arab allies and oil shipments in the Persian Gulf, which would draw the U.S. military into the fray.

In pressing for nuclear talks with Iran earlier this year, Trump initially suggested a two-month time frame for negotiations to succeed. That deadline was reached on Thursday. The Israelis feared that the talks could drag on as Iran’s nuclear efforts advanced.

President Donald Trump, right, listens as White House special envoy Steve Witkoff, left, speaks during a swearing in ceremony for interim U.S. Attorney General for the District of Columbia Jeanine Pirro, Wednesday, May 28, 2025, in the Oval Office of the White House in Washington. (AP Photo/Evan Vucci)

But there had also been more hopeful speculation for weeks that the threat of Israeli or American military action might enable Witkoff’s diplomacy by pressuring Tehran to yield to demands that it scale back its nuclear program and stop enriching uranium.

Yet after five rounds of talks in which the two sides appeared to remain far apart, it was the diplomatic process that enabled Israel’s military campaign

Taking a page from its campaign against Hezbollah in Lebanon, Israel put a premium on strikes to decapitate its adversary’s military leadership even as it targeted key nuclear facilities. But doing that successfully required a surprise, and Israeli officials had to confront the challenge that they had long telegraphed their punch. Striking before Witkoff’s coming meeting in Oman offered a way out.

Trump has said repeatedly that he favored solving the Iran nuclear issue diplomatically. “We remain committed to a Diplomatic Resolution to the Iran Nuclear Issue!” Trump wrote Thursday on Truth Social before the Israeli strikes were under way.

But Iran’s conspiracy-minded hard-liners are already inclined to see an American hand in Israel’s military operations. And some former U.S. officials say it won’t be easy for Trump to distance himself from Israel’s military operation.

Aaron David Miller, the former U.S. Middle East peace negotiator, said that there are no indications the White House was so opposed to an Israeli military strike that it was prepared to put the U.S.-Israeli relationship on the line. Israel, he said, was given a “plausible denial green light.”

A man and his sons watch smoke from Israeli bombardment billowing over buildings in the northern Gaza Strip, from an overlook in Sderot, southern Israel on the Jewish holiday of Shavuot, Monday, June 2, 2025. (AP Photo/Maya Alleruzzo)

Write to Michael R. Gordon at michael.gordon@wsj.com