President Donald Trump said Thursday he would decide in the next two weeks whether the US will get involved in the Israel-Iran air war.
Trump's self-imposed deadline follows significant buildup of US military equipment in the area and puts pressure on Iran and a European-led effort to de-escalate the ongoing conflict.
Should the US become involved directly in airstrikes, numerous bases it operates from, dotted across the Middle East, might support attacks against Iran as well as become possible targets for retaliatory missile strikes.
The US has already moved some aircraft and ships from bases that may be vulnerable to any potential Iranian attack, two US officials told Reuters on Wednesday. The US embassy in Qatar also issued an alert on Thursday temporarily restricting its personnel from accessing the Al Udeid Air Base, the largest US military installation in the Middle East, which is located in the desert outside Doha.
Washington has also begun deploying more fighter aircraft — including F-16, F-22 and F-35 fighters — to the Middle East and extending the deployment of other warplanes, bolstering forces that can defend personnel and facilities by shooting down drones and other projectiles, US officials said.
Other recent examples of the US military buildup in the region include:
Why Israel may need the US to attack Iran to achieve its goals
Israel's command of Iranian air space leaves few obstacles in the way of its expanding bombardment, but it will struggle to deal a knock-out blow to deeply buried nuclear sites without the US joining the attack, experts say.
Chief among these is Iran's Fordow nuclear facility, which according to the International Atomic Energy Agency, has thus far suffered little or no visible damage from Israel's air campaign.
Dug into a mountain, Fordow produces the vast majority of Iran's uranium enriched to up to 60%, which could be refined further to weapons-grade material.
The heart of the facility is buried up to 80-100 metres deep and is inaccessible to all but the most powerful US bunker buster bombs.
The Fuel Enrichment Plant at Natanz is buried even deeper than Fordow. However, the IAEA estimates that an earlier Israeli attack on the plant's energy infrastructure has effectively destroyed the plant's uranium enrichment centrifuges. But destroying the facility altogether is beyond the firepower Israel alone can deliver from the air.
If Trump decides to use US forces against facilities like Fardow, he may opt to send the US Air Force's B-2 Spirit stealth bomber.
The bomber's internal weapons bays are specifically designed to maintain stealth characteristics while accommodating large ordnance loads which could include two GBU-57A/B MOP (Massive Ordnance Penetrator), a 30,000-pound precision-guided "bunker buster" bomb.
The MOP represents the largest conventional bomb in the US arsenal, specifically engineered to defeat hardened underground bunkers. Its massive size provides unmatched bunker-penetration capability, while the weapon's 20.5-foot length and GPS-guided precision targeting system enable accurate strikes against specific underground facilities. Its penetration capability of over 60 metres (200 feet) through hardened concrete makes it effective against the world's most protected underground installations.
In order to destroy the facility at Fardow, which may be buried as much as 100 metres underground, bombers may need to drop multiple MOPs in succession on the same target.
According to a 2012 Congressional Research Service report, reaching the facility directly may not be necessary to disrupt or destroy the centrifuges it contains:
"The question would be how well the centrifuges have been isolated from shock and the possible blast effects of an attack."
But if the goal of any US or Israeli campaign is to ultimately destroy these facilities, success is not guaranteed, even with such powerful bombs.
Andreas Krieg, a senior lecturer at the School of Security Studies at King's College London, said even the heaviest US bunker-busting bombs might struggle to penetrate Iran's deepest sites — in the event President Donald Trump decides to join the attack — suggesting special, commando-style forces might be needed on the ground to completely destroy the facilities.
