In a 48-hour arc that moved faster than any diplomatic development since February, the United States and Iran signed a 14-point memorandum of understanding — then watched Israel continue strikes in Lebanon, prompting Tehran to close the Strait of Hormuz within hours of the ink drying.
Strait of Hormuz — Iran declared the strait closed Saturday, citing Israeli strikes in Lebanon as a violation of the 14-point US-Iran memorandum of understanding signed just days earlier. The US military disputed the claim, saying the channel remains navigable.
President Trump announced on Sunday, June 15, that the US and Iran had reached "a great deal" — a memorandum of understanding signed by both parties that included a 14-point framework covering a ceasefire extension, the reopening of the Strait of Hormuz, and a commitment to begin nuclear negotiations in Switzerland. The announcement, mediated through Pakistan's prime minister and formalized in Geneva, sent crude oil markets sharply lower and equity markets higher on Wednesday as traders priced in a diplomatic resolution to the four-month conflict.
The relief lasted fewer than 48 hours. Israel continued airstrikes on Lebanese territory in the days following the MOU signing, which Tehran interpreted as a direct violation of the agreement's first clause — a stipulation that combat operations cease on all fronts, including Lebanon. Iran's military announced Saturday that it had closed the Strait of Hormuz in response. The United States military disputed the claim, with CENTCOM stating that the strait remained navigable for commercial traffic and that US naval forces continued to operate in the region without obstruction.
Vice President JD Vance, who had been scheduled to lead the American delegation in Lucerne for the first round of nuclear talks on Friday, saw his departure delayed when Iran announced it was postponing negotiations due to the continued Lebanon fighting. Vance departed late Saturday afternoon from Joint Base Andrews and is now en route to Switzerland, with the White House indicating talks may resume Sunday or Monday if conditions allow. A senior administration official said the 60-day window established by the MOU "began Thursday," and the clock is running regardless of when Switzerland talks formally convene.
The Israeli government has not publicly acknowledged that its Lebanon operations constitute a violation of the MOU. Israeli officials have characterized the strikes as targeting Hezbollah infrastructure that was not covered by the ceasefire's geographic scope. Iran rejected that interpretation. The Lebanese government called the continuing strikes a "flagrant violation of sovereignty." Meanwhile, an Israel-Hezbollah ceasefire agreed at 9 a.m. Eastern on Friday held briefly before both sides resumed fire, with heavy exchanges reported across southern Lebanon through Saturday evening.
The macroeconomic stakes remain severe. The 14-point MOU included provisions for unfreezing Iranian funds and establishing a $300 billion reconstruction fund — conditions that drew sharp criticism from Republican senators who had not been consulted. If the agreement holds and the Strait of Hormuz reopens fully, estimates from Goldman Sachs suggest crude oil could fall $18 to $22 per barrel. If it collapses, the prior market trajectory resumes. As of Saturday evening, markets have no clear answer, and traders will price the uncertainty when equities open Monday morning.
