Trump also said the US may do another "Epic Fury" — the codename for America's last military campaign against Iran.
Iran's Revolutionary Guard is already warning that any attack gets hit back several times harder.
That's everything we know.
Why this mattersSo this war never actually ended.
America and Israel went to war with Iran back in February. A ceasefire came. Both sides agreed to finalise a peace deal.
That deal has now collapsed. And both sides are back to threatening each other, in public.
Here's the twist. A couple of weeks ago Trump promised the opposite. He wrote that the US would not attack Iran before the midterm elections. The White House repeated that promise just days ago.
Now he's saying tomorrow.
And the military build-up behind it is real. More than 50,000 US troops are in the Middle East right now. About 20 warships. Two aircraft carrier strike groups, with a third — the USS Theodore Roosevelt — on its way. Plus 4,000 Marines and sailors aboard three ships led by the USS Makin Island.
The Pentagon says its job is to build military options for the president, and that it won't speculate on future operations. It won't say whether Trump has actually approved anything.
So here's the question nobody can answer yet. Gregory Brew, an Iran expert at Eurasia Group, says it looks likely the US goes back to strikes once the midterms pass. Harrison Mann, a former Defense Intelligence Agency officer, points out the US has mostly held off since April, hitting only targets on Iran's coast.
Iran isn't just posturing either. President Masoud Pezeshkian blames Washington for the collapse of the interim deal, but says both sides should go back to it. Iran's government spokesperson, Fatemeh Mohajerani, says quote "Tehran will not wait for permission to defend itself". Iran's armed forces chief of staff, Ali Abdollahi, says US warships won't enter the Gulf under any circumstances, at any time.
And Iran has its own plan ready. Two senior Iranian security officials have told Reuters that Tehran could hit undersea internet cables in the Gulf if the war resumes. A senior figure in Iran's Revolutionary Guards says Iran could target seven major cables under the Strait of Hormuz. The secretary of Iran's Supreme National Security Council has named cables, data centres and AI facilities as possible targets too.
America's Director of National Intelligence has also warned, in a memo to the Secretary of State, that Iran has plots against US staff in the Middle East that are nearly ready to go.
Oil markets already feel it. Brent crude passed $117 a barrel this week — the highest since May.
So what don't we know? Whether Trump's "tomorrow" is a real deadline or just pressure talk. Whether the Pentagon's plans actually have his sign-off. Israel votes in three days. America votes in ten.
