As Tehran and Washington hold tough negotiations to avert war, the pair have been at odds over longstanding issues: Iran’s nuclear programme, its ballistic missile arsenal and its network of proxy groups in the region.
Tehran’s atomic programme has for decades been an area of contention with the west. US President Donald Trump’s lead negotiator, Steve Witkoff, claimed last weekend that Iran was “probably a week away from having industrial-grade bomb-making material”, but secretary of state Marco Rubio subsequently said Iran was “not enriching [uranium] right now” — though, he added, it wanted to.
Washington also wants the talks to cover Iran’s ballistic missiles and network of regional militant groups, such as Hizbollah, arguing they threaten regional stability and US assets.
Here is what independent experts say about these areas of Iranian power.
What is the state of Iran’s nuclear programme?
Based on satellite imagery and monitoring of nuclear sites, experts say Iran’s uranium-enrichment programme appears to be on hold, following Israeli and US attacks last June that severely damaged its nuclear sites.
In that conflict, the US used 30,000-pound “bunker buster” bombs on the main enrichment facilities, Natanz and Fordow, and fired missiles at a third site in Isfahan.
“We have not seen any evidence that Iran is trying to reconstitute its nuclear weapons programme or enrich uranium.,” said David Albright, a physicist and weapons expert who is the founder of the Institute for Science and International Security in Washington.
However, he said, “the lack of transparency around Iranian nuclear activities leads to uncertainty and worst-case assessments, which will be harder to refute as time goes on and activities continue”.
Before those attacks, the International Atomic Energy Agency said Iran had 400kg of uranium enriched to 60 per cent. Iran says that stockpile is buried beneath the rubble, but its fate is a concern for western governments.
Uranium enriched to 90 per cent is considered weapons grade.
Today, even if Iran still holds these stocks of highly enriched material, rebuilding or reactivating enrichment capacity would take months rather than weeks, said US and Israeli experts.
American assessments have been contradictory. After claiming for months that the US had “obliterated” Iran’s nuclear programme, Trump said on Tuesday that Iran was “at this moment” pursuing its “sinister” ambition of acquiring a nuclear weapon.
Iran has long insisted it is not seeking nuclear weapons, while President Masoud Pezeshkian this month said the country was open to “any kind of verification”. It was unclear if that would amount to a change to what the International Atomic Energy Agency has said was its recent approach of allowing only partial inspections of its sites.
Albright said activity observed in satellite photos since last June’s war related mostly to recovery operations or hardening underground tunnel entrances.
He said a new building was under construction at the bombed headquarters of the defence ministry research facility in Tehran.
What ballistic missiles does Iran have and how could they be used?
Iran considers its vast, mostly homegrown missile and drone arsenal to be its main deterrent against US and Israeli attacks. “Iran is a one-trick pony,” said Danny Citrinowicz of the Institute for National Security Studies in Tel Aviv.
Rubio said this week that the Islamic republic had “thousands of short-range ballistic missiles” that threatened US forces and its bases and partners in the region, alongside naval assets that “threaten shipping and try to threaten the US Navy”.
Iran’s ballistic missile arsenal was depleted in the 12-day war with Israel last year. It fired roughly 550 medium- to long-range missiles, while many more were destroyed on the ground by Israeli air strikes.
To replace these, Tehran had been producing missiles around the clock since then, Citrinowicz said. “They are returning back to where they were before [the war] but [are] not there yet.”
Experts, including Lynette Nusbacher, a former senior intelligence adviser to the UK cabinet on the Middle East, said it was plausible that Iran’s short-range ballistic missile arsenal, with ranges between 300km and 1,000km, still numbers in the thousands.
These could hit US bases in the Gulf and elsewhere in the Middle East. Israel did not target these systems during the war.
Iran has a number of ageing Chinese-made anti-ship missiles deployed on shore or on fast attack craft. Its anti-ship missiles could be used against commercial shipping, including oil tankers, and against US naval vessels, said Nusbacher.
How strong is Iran’s network of regional proxies?
US officials have long pointed to Iran’s allied militant groups across the Middle East as evidence of its position as the world’s “largest state sponsor of terror”.
But Hamas’s October 7 2023 attack on Israel triggered a wave of conflict that battered Tehran’s so-called Axis of Resistance, including Hizbollah in Lebanon, Hamas in the Palestinian territories, the Houthis in Yemen and Shia militias in Iraq.
Hizbollah has long been seen as Lebanon’s most potent military and political force and the crown jewel in Iran’s network. Its strength has waned after a bruising full-scale war with Israel in 2024 in which its former leader Hassan Nasrallah and much of its senior leadership were assassinated.
The group largely sat out the war between Iran and Israel last June, but there is growing debate about whether it would participate in a wider regional conflict at Tehran’s request.
Experts estimate it still retains 20 to 30 per cent of its missile arsenal and tens of thousands of fighters, but Israeli surveillance has impaired Hizbollah’s ability to mount attacks. “As soon as a missile launcher pops up anywhere, the Israelis take it out,” said Maha Yahya of the Carnegie Middle East Center in Beirut.
The Institute for the Study of War think-tank this month said Hizbollah was “preparing militarily for another round of conflict with Israel, possibly to deter an attack and make Israeli military pressure less effective”.
It might be “reinforcing its positions in Lebanon’s mountainous northern and central areas”, the ISW said.
Iraq’s Shia militias largely avoided the tumult that followed October 7. On Thursday, one group close to Tehran, Kataib Hizbollah, called on its fighters “to prepare for a long war of attrition” should America launch a conflict in the region.
Yemen’s Houthi militants, meanwhile, have been seen as one of the more effective groups in Tehran’s axis. They have struck shipping in the Red Sea as well as directly targeting Israel. The Houthis have suggested they would support Iran in a renewed confrontation.
Earlier this month, the group staged a mass protest in the capital, rallying under the slogan “Steadfast and ready for the next round”.
“Iran’s proxy network has been damaged but not defeated,” said Bridget Toomey of the Foundation for the Defense of Democracies, a Washington-based think-tank.
Are other issues coming into play between Iran and the US?
When Tehran brutally cracked down on large-scale protesters earlier this year, Trump said he could intervene to “rescue” the demonstrators and claimed that Iran backed off carrying out hundreds of executions because of his threats.
Iran, meanwhile, wants relief from sanctions, many of which were introduced in waves after Trump abandoned a nuclear deal with the Islamic republic during his first term. Tehran also wants access to its assets that have been frozen abroad.
Satellite image visualisation and cartography by Steven Bernard and Cleve Jones