What are the nuclear options now open to the US?
President Trump is considering sending troops to secure Iran’s enriched uranium after reports of US-Israeli strikes on one of the main sites that he said was obliterated last year.
Missile attacks caused “severe damage” to an irradiation sterilisation facility in Isfahan on Saturday, Iran’s ISNA news agency reported. The Iranian regime has not allowed any inspection at Isfahan, where most of the uranium was believed to be stored, nor at Fordow and Natanz, the main places for enrichment.
All three were seriously damaged in June and satellite images show some work compatible with securing them but no sign of any serious attempt to reconstitute the programme. Most of the enrichment centrifuges are believed destroyed, while the uranium stored in gas form in canisters is thought to be buried deep under rubble.
Smoke after explosions in Isfahan on Saturday and, below, Isfahan Nuclear Technology Centre before it was hit by US airstrikes last year
REUTERS
Iran is believed to have 440kg of uranium enriched to 60 per cent, enough if increased to 90 per cent to build 11 nuclear warheads.
Not even the International Atomic Energy Agency (IAEA) knows the exact location of the entire stockpile, which it had previously verified, or whether it is retrievable. Other sites may have uranium; the Iranians were working on a back-up facility near Natanz deep underneath Pickaxe Mountain, which was not targeted last year. Israel claims to have evidence of secret sites it is now targeting.
“It was a total obliteration, they haven’t been able to get to it,” Trump said on Air Force One when asked about sending in US troops. “At some point maybe we will. It would be a great thing. But right now we’re just decimating them. But we haven’t gone in. It’s something we can do later on.”
Trump has made ending Iran’s nuclear weapon ambitions one of the US aims but there are no easy options:
Further bombing raids
The main sites were struck in June by Israeli strikes, US GBU-57A/B massive ordnance penetrator (MOP) bombs dropped by B-2 stealth bombers and submarine-launched Tomahawk cruise missiles.
While the MOP “bunker busters” can penetrate up to 60m of concrete before detonating, the condition of the uranium is unknown.
A B-2 strategic bomber and, below, a Tomahawk cruise missile
ALAMY
US NAVY PHOTO/AFP/GETTY IMAGES
By devastating Iran’s defences, the US and Israel will eventually acquire uninterrupted air superiority, enabling them to target with impunity.
Cruise missiles would not require the same level of air superiority but do not have the penetrating power of MOPs.
The precise whereabouts of the uranium is unknown and so hard to target precisely by bombing.
Any more attacks will further inhibit access by the Iranians but will not end questions about how much remains buried and whether any of it was spirited away.
The only categoric reassurance that the uranium is beyond Iranian use would come from seizing the material.
Ground troops
This would be the most obvious means of securing the nuclear stockpile from the point of view of a regular military textbook and is thought to have been war-gamed by the Pentagon.
However, Iran is a large and well-defended country and entering the underground sites is a complex issue, especially if the entrance tunnels have been blocked. Special forces would require excavating equipment and may have to operate in protective gear if any leak of the gaseous uranium is detected. It would be a risky task even if there was a joint US-Israeli mission with larger numbers of troops to defend the perimeter.
This seems like an effort to be reserved for the case of regime collapse.
A deal with the Islamic Republic
The US and Iran were, via Omani mediators, negotiating a deal to restrict Iran’s nuclear programme when the current operations began.
If Trump feels the war has gone on long enough, negotiations could resume, with Iran under more pressure to accept that enrichment must end.
WHITE HOUSE/AFP/GETTY IMAGES
Various inducements have been offered: the provision of already enriched uranium for its nuclear power plant, for example. But Iran has up until now insisted that maintaining an enrichment programme is its right as a sovereign country, insisting this is only for peaceful purposes.
Regime change
A US-friendly government in Tehran could solve all problems of access and verification. In an ideal world for Trump and Netanyahu, a pro-western regime would arise after a popular overthrow of the Islamic Republic and agree to settle the nuclear issue, ending the programme with the uranium transferred out of the country, supervised by the IAEA.
Apart from the question of whether regime change can be achieved, there is one relatively unconsidered possibility: that a new, secular, nationalist government might meet the West’s concerns on some issues but out of patriotic fervour insist on retaining a nuclear programme. That would present the West with a new dilemma.