Three sticking points that could derail the US-Iran deal to end the war

After weeks of talks, the United States and Iran have reached a preliminary agreement, but attention is already turning to the formidable challenges of ending the war.

On Wednesday, senior US officials read a 14-paragraph memorandum of understanding to journalists, including at the BBC.

The agreement was signed by US President Donald Trump and Iranian President Masoud Pezeshkian earlier than expected – it was due to be officially signed in Switzerland on Friday – paving the way for a “final deal” to be reached in “a maximum of 60 days, extendable with mutual consent.

It sets out commitments to begin lifting the US naval blockade, restore navigation in the Strait of Hormuz and negotiate the lifting of “all types of sanctions” against Iran. The document also outlines plans for a fund of at least $300 billion (£224 billion) for Iran’s reconstruction and economic development, as well as a renewed commitment from Tehran not to develop a nuclear weapon.

Trump warned that the preliminary agreement was “not final” and said the United States could “go back to dropping bombs” if it failed.

Iranian Parliament Speaker and key negotiator Mohammad Bagher Ghalibaf told state media that his distrust of the United States persisted and that Iran “had its finger on the trigger.”

Here are three of the main threats that could compromise the negotiations, according to experts.

Both sides declared “the immediate and permanent cessation of military operations on all fronts, including in Lebanon,” said Pakistani Prime Minister Shehbaz Sharif, who acted as one of the main mediators when the initial agreement was announced.

The agreement, read Wednesday, also explicitly includes Lebanon, guaranteeing its “territorial integrity and sovereignty.”

Israel, however, continued its strikes against Lebanon, even after Trump declared that his Israeli counterpart Benjamin Netanyahu should be “more responsible towards Lebanon” during the G7 summit in France.

On Wednesday, Israeli planes struck the Nabatieh al-Fawqa area and the outskirts of the neighboring town of Kfar Tebnit, the Lebanese state-run National News Agency (NNA) said.

Additionally, US officials say that while Lebanon is covered by the ceasefire framework, the withdrawal of Israeli forces from Lebanese territory is not a condition of the agreement. Israel will retain the right of self-defense, they add.

But Iran said ending the war in Lebanon was “an inseparable element of the agreement to end the war.”

Hezbollah, the Iranian-backed militant group in Lebanon, shares this position. Iran has assured its ally that it will demand the full withdrawal of Israeli troops from Lebanon in the next phase of negotiations, Hezbollah’s media relations office told Reuters.

Israel also made clear that it did not consider itself bound by Iran’s interpretation of the deal. Defense Minister Israel Katz said Israeli forces would remain in Lebanon’s security zones “with no time limit” and warned that they would “strike with all their might” if Iran attacked Israel “over Lebanon.”

Tel Aviv has been the “main obstacle” to peace efforts, says Dr HA Hellyer, a political scientist at the Royal United Services Institute, a British think tank.

“Israeli military adventurism, whether directed against Iran or carried out in the context of the continuing devastation in Lebanon, represents the greatest threat to diplomatic progress,” he says.

The process could fail even before “substantial negotiations on the nuclear issue begin” if Tehran is drawn into a direct confrontation, Hellyer says.

Lebanese President Joseph Aoun welcomed the preliminary agreement, hoping it will result in “practical measures that will definitively end the cycle of violence.”

For Lebanon itself, the consequences of the war were devastating. More than 3,700 people were killed, around a million people were displaced, and much of the south suffered widespread destruction.

Another sticking point is Iran’s enriched uranium, even though Trump has said there is no urgency to confiscate it.

According to the International Atomic Energy Agency (IAEA), Iran had accumulated around 400 kg of uranium enriched to 60% last year. For a nuclear weapon, the enrichment rate is around 90%.

Tehran has always maintained that its nuclear program is peaceful and reaffirmed in the agreement that it will not seek to develop nuclear weapons.

However, key issues, including the treatment of existing enriched materials, still need to be negotiated as part of a final agreement.

Both sides agreed in principle to decide how to deal with stockpiles of enriched materials. At a minimum, the uranium will be “down mixed”, that is to say diluted, on site under the supervision of the IAEA

As part of the 2015 nuclear deal negotiated by President Barack Obama, Tehran limited enrichment to 3.67%. After the United States withdrew in 2018, during Trump’s first term, Iran significantly expanded its nuclear program.

The president “will likely resume military operations” if he senses that Iran is once again enriching weapons-grade uranium, Darin Selnick, former deputy chief of staff to U.S. Defense Secretary Pete Hegseth, told the Today show. from BBC Radio 4.

For now, both sides are expected to maintain “the status quo” during the 60-day negotiation period: Iran will not expand its nuclear activities, while the United States will refrain from imposing new sanctions or increasing its military presence in the region.

The agreement also aims to reopen the Strait of Hormuz, which has been paralyzed since February. Before the war, around 20% of the world’s oil and gas supplies passed through this key maritime route.

It says the waterway will be reopened after the deal is signed on Friday, and all operations are expected to be completed within 30 days once technical and security obstacles are removed, including mine clearance by Iran.

The agreement stipulates that the strait will remain free for an initial period of 60 days, “from the Persian Gulf to the Arabian Sea and vice versa.” It added that Iran will hold discussions with Oman and other Gulf states on the future administration of the waterway and maritime services, in accordance with international law.

This would open the possibility of some charges becoming a reality in the future.

Tehran has already indicated that it wishes to play a more important role in the management of the strait. Iranian Foreign Ministry spokesman Esmaeil Baghaei said Iran would charge service fees for ships crossing the strait. However, it is unclear exactly what these would cover.

Passage tolls are not permitted under international law, although charges for specific services are permitted.

The American side, however, said it was convinced that the strait would remain free of tolls after the negotiations.

The US official said Iran may seek to assert its position, but Gulf states will not agree to any arrangements limiting free access.

Trump said Iran would act with “common sense” and not impose costs because the move could lead to further military escalation. The United States also believes that the Gulf states would “never” accept a future system involving tolls.

Practical questions also remain unanswered.

Mine clearance could also take “weeks or even months,” retired US Navy Rear Admiral Mark Montgomery told the BBC.

Shipping companies are likely to proceed with caution until they are satisfied that the ceasefire is respected.

“It would take an extremely brave captain to cross the Strait of Hormuz, given the current state,” Martin Kelly of crisis management firm EOS Risk Group told BBC Verify.

Hellyer warns, however, that the agreement to end the war is only “a memorandum of understanding, a negotiating framework, not a solution.”

“The hard work hasn’t started yet,” he adds.