The Islamic Republic of Iran violated a Tuesday morning cease-fire six hours after President Trump announced it, putting in peril a possible end to the 12-day Iran-Israel war. Israel sent jets to act in response, raising the president’s ire. 

“We basically have two countries that have been fighting so long and so hard that they don’t know what the f— they’re doing,” he told reporters.

Mr. Trump called Prime Minister Netanayhu after publicly accusing both sides of violating the spirit of the cease-fire he brokered, and warned Israel not to retaliate. After the conversation, the president wrote on Truth Social that the cease-fire was back on. 

“Israel is not going to attack Iran,” he wrote. “All planes will turn around and head home while doing a friendly ‘plane wave.’ Nobody will be hurt. The ceasefire is in effect.”

The Israeli Defense Force struck in Iran in the first hour after the president announced that a cease-fire would come to effect within six hours. Iran hit an apartment building at the southern Israeli city of Beersheba, killing four people, in a salvo that continued even after the designated time for the onset of the cease-fire.  

“I’m not happy with Iran, but also with the other side,” Mr. Trump told reporters. “Israel, as soon as we made the deal, they came out and they dropped a load of bombs, the likes of which I’d never seen before, the biggest load that we’ve seen. I’m not happy with Israel.”

Mr. Trump added, “When I say, ‘Okay, now you have 12 hours,’ you don’t go out in the first hour and just drop everything you have on them. So I’m not happy with them. I’m not happy with Iran either, but I’m really unhappy if Israel’s going out this morning, because the one rocket that didn’t land, that was shot, perhaps by mistake, that didn’t land.” He then used an expletive.

The bomb did land, though. Four Israeli civilians were killed and dozens injured after an Iranian ballistic missile struck residential apartment buildings at Beersheba. It was part of a large barrage of Iranian ballistic missiles just prior to 7 a.m., Israel time. Additional missiles were also launched from Iran after that hour, which Mr. Trump designated for starting a cease-fire that was agreed to by the two sides. 

As the Iranian foreign minister, Abbas Araghchi, earlier announced that the cease-fire has been accepted by Iran, it wasn’t clear if the Islamic Republic leader, Ayatollah Khamenei, was in full control of the regime’s military. Either way, Israel saw the deadly attack as a Tehran violation that could void the pact. The Israel Defense Force was on alert for a possible retaliation.  

“I have instructed the IDF, in coordination with the Prime Minister, to respond forcefully to Iran’s violation of the ceasefire with powerful strikes against regime targets in the heart of Tehran,” the defense minister, Israel Katz, wrote on X. “The Iranian regime has seriously violated the ceasefire declared by the US President and launched missiles at Israel, and in accordance with the government’s policy as determined – we will respond forcefully to any violation.”

The Qadr missile that struck Beersheba is one of the largest in Iran’s arsenal, carrying a payload of 900 pounds. “You see the destruction here and the heavy price,” President Herzog said on a visit to the ruins of the apartment building. “We need to remember that this is an opportunity to say that Operation Rising Lion was a huge success.”

Israel, Mr. Herzog said, “removed the Iranian nuclear threat for a significant stretch of time. I can’t yet analyze exactly all the results, but there is no doubt that there are huge achievements to this operation.” He thanked Mr. Netanyahu, the government, and the military.

Shortly after 6 p.m. EDT Monday, Mr. Trump announced an end to what he called “the 12-day war” between Israel and Iran. The name might have alluded to Israel’s spectacular 1967 victory over Arab countries, known as the Six-Day War.