Storylines explainer Trump administration

US-Iran war and Hormuz negotiations

The US has been at war with Iran since February. Now Iran is offering to reopen a vital oil route within days, on terms that would require difficult concessions from Donald Trump.

Drawn from 6 Guardian articles published 14–25 September 2026 · About a five-minute read · Watch the 30-second video

In short

  1. The US and Israel launched joint strikes on Iran in February. Since early in the war Iran has had a stranglehold on energy shipping through the strait of Hormuz,2 and reopening it is expected to relieve pressure on global energy markets.5
  2. The war is hugely unpopular in the US, the Guardian reports.3 Congress’s budget office puts the cost at $38bn or more, and the House of Representatives has voted three times to end it.1
  3. During the UN general assembly in New York, Iran offered to reopen the strait within days if the US makes big concessions, including an end to the fighting in Lebanon. Iran is waiting for Trump’s answer.4

The basics

What is the strait of Hormuz?

A key waterway for transporting oil.3 Oman lies on its south side.5 The latest published figures suggest fewer than five identifiable tankers a day are getting through, though US navy estimates are much higher.3

What was the June deal?

On 17 June the US and Iran agreed a memorandum of understanding.3 Trump signed it.4 Its implementation fell apart after each side accused the other of breaking it by trying to take control of the strait, though Iran’s president says it remains the starting point.3

How is the US squeezing Iran?

Through sanctions and a naval blockade that makes it nearly impossible for Iran to export oil, depriving it of badly needed foreign currency.3

What happened, in order

  1. February

    The war begins

    The US and Israel launched joint strikes on Iran.2

  2. June–July

    A deal, and votes to end the war

    The US and Iran agreed a memorandum of understanding on 17 June; its implementation later fell apart.3 In June and July the House passed resolutions to end US action in Iran.1

  3. Tuesday15 Sept

    The bill arrives

    A Congressional Budget Office report put the cost of the war at $38bn or more, and estimated it would grow by $3bn for every month it continues, depending on its intensity. Defending against Iranian missiles and drones has used up so many interceptor missiles that rebuilding the stockpile “would probably take at least five years, even if production was increased”, the CBO said. A few hours after the report, the House voted 220 to 204 to end the war, its third such vote. In a White House statement responding to reports of shortages, Trump said the US had “far more munitions than anyone in the world”.1

    None of the House resolutions has reached the president, who would almost certainly veto them. Earlier, the Senate also passed one, on its 10th attempt, but Republican senators reversed course the next day after Trump berated them.1

    The Pentagon’s own review of the war, released the day before, did not address its internal investigation into a strike on a school in Minab on the war’s first day, which killed 156 people, including 120 children.1

  4. Tuesday22 Sept

    Trump at the UN

    In a speech to the UN general assembly, Trump said: “I call on all nations to help to enforce the complete economic isolation of Iran.” He said he had a “big decision” to make: a deal, or “do I annihilate the Islamic republic and do it quickly”. He said the midterm elections would not affect his decisions: “The only thing that does is that Iran will never have a nuclear weapon.”2

  5. Reported23 Sept

    Talks in a UN room

    Iran’s foreign minister, Abbas Araghchi, met Trump’s envoys Steve Witkoff and Jared Kushner for three hours at the UN headquarters, with Qatar mediating. Trump said the talks had been very productive, and the price of Brent crude oil fell below $100 a barrel for the first time in two weeks. Iran denied it had dropped its conditions. Its foreign ministry said the aim was to convey demands including “the end of the war in all its dimensions”.3

  6. Thursday24 Sept

    Iran’s offer

    Iran said it had told Trump it would reopen the strait and start nuclear talks within a week if the US met its conditions. “We have introduced a plan to the US through the mediators,” Araghchi said. Saudi Arabia had been expected to endorse the new shipping route the week before but pulled back, partly out of anger at attacks on it by the Iranian-backed Houthis in Yemen. Brent crude was trading at about $107 a barrel,4 against $64 before the fighting.1

Iran’s seven-day timetable

Iran’s offer, as reported by the Guardian from New York on 25 September. A Guardian headline the day before described it as opening the strait “in six days”: the strait reopens on day six and nuclear talks follow on day seven. Select a stage to see what it involves.

Days 1 to 5: The US acts

  • Lift the naval blockade on Iran’s oil ports5
  • Restore the waiver that lifted sanctions on Iran’s oil exports5
  • End the war on all fronts5
  • Allow the release of some of Iran’s frozen assets5
The catch

Patrick Wintour writes that the hardest step for Trump is probably ordering Benjamin Netanyahu to end Israel’s attacks on Hezbollah in Lebanon. Iranian diplomats say a deal would be feasible if Trump could rein in Netanyahu in Lebanon.5

Day 6: The strait reopens

  • Iran reopens the strait of Hormuz5
  • Ships use a new route designated by Oman and Iran5
The catch

The new route runs mainly through Iranian waters. Wintour writes that the strait would reopen largely on Iran’s terms. Saudi Arabia is concerned that the route deal is between Iran and Oman only, without the other Gulf states as joint signatories.5

Day 7: Nuclear talks begin

  • Talks start on the future of Iran’s civil nuclear programme5
  • Including a protocol to let UN nuclear inspectors back in to Iran’s damaged sites and its stockpile of highly enriched uranium5
The catch

Under the June agreement, these talks would not have started for 60 days.4

When would nuclear talks begin?

June agreementDay 60
Iran’s new offerDay 7

Who’s who, and where they stand

Around the table

Is it even a war?

This is the only opinion piece in the Storyline.

What happens next

Araghchi said he would stay in New York over the weekend to wait for an American answer, but was not in a hurry.4 The US midterm elections are in November, and the White House is under pressure to bring down oil prices before then.3 For Patrick Wintour, the real question for Trump is whether he is prepared to go back to war after the midterms, and if not, whether he believes the US can squeeze Iran’s economy until its leadership gives in.5

Read more

Every fact on this page comes from these Guardian articles. The numbers match the source links in the text.

Key stories

  1. US House votes for third time to end Iran war after $38bn cost is revealedJoseph Gedeon and Andrew Roth in Washington · 15 September 2026
  2. Trump calls on allies to enforce ‘complete economic isolation of Iran’ in UN speechAndrew Roth in New York · 22 September 2026
  3. Iran denies dropping preconditions amid ‘very productive’ three-hour UN talks in New YorkPatrick Wintour in New York · 23 September 2026
  4. Iran awaiting response from Trump on proposal to open strait of Hormuz in six daysPatrick Wintour in New York · 24 September 2026
  5. Trump faces tough choices as Iran dangles deal to reopen Hormuz before US midtermsPatrick Wintour in New York · 25 September 2026

Opinion

  1. The situation in Iran is dangerously escalating – but whatever you do, don’t call it a warArwa Mahdawi · 14 September 2026