Is the US preparing for direct military action in Iran?

On 16 June, at least 31 refuelling aircraft departed from American bases towards Europe, landing at key stopover points for Middle East operations. Though US officials decline to comment on the exact number of such aircraft deployed, a fleet of 31 such planes can support well over 200 combat aircraft operating simultaneously.

The deployments, according to Reuters, suggest the US is greatly strengthening its air power for potentially sustained operations in Iran. 

Meanwhile, on the other side of the world, the USS Nimitz carrier strike group has cancelled its scheduled port call in Vietnam and left the South China Sea, Reuters reports. It is now headed toward the Middle East to join aircraft carriers already stationed there. This type of buildup typically signals preparations for a large-scale air campaign.

If the US intends to support Israel's campaign, these refuelling planes and aircraft carriers would be among its most critical assets. 

For days, Israeli Prime Minister Netanyahu has urged US President Donald Trump to join the war against Iran. Whether Trump will give in to the pressure remains to be seen, but US military preparations seem to be pointing to it. 

Satellite imagery shows the extent of damage at Natanz, Iran's main uranium enrichment facility. Key buildings have been leveled, and more than a dozen top scientists have been killed. One such building was used to convert weapons-grade uranium into uranium metal, the core of a nuclear weapon. Rebuilding it could take up to a year.

Israel's best bunker busters, such as the US-supplied GBU-28, can penetrate up to 6 metres of concrete — nowhere near enough for Pickaxe or even Fordow. The only weapon that stands a chance is the GBU-57 Massive Ordnance Penetrator. This 13,000 kg bomb can punch through 61 metres of concrete. It is the most advanced bunker buster in existence, but only the US Air Force can deploy it using the B-2 bomber.

However, the real problem remains: Iran's most protected site, the Fordow fuel enrichment plant, is buried deep inside a mountain near Qom. Encased in reinforced concrete, Fordow is believed to be beyond the reach of any known Israeli weapon. Built in secret and publicly unveiled in 2009, it has been central to international efforts to curb Iran's nuclear ambitions.

But Iran has other ultra-secure facilities beyond Fordow. According to an AP report in 2023, Tehran has been constructing an even deeper, more fortified site known as the Pickaxe Mountain Plant, located a few kilometres south of Natanz. While Fordow is believed to have two tunnel entrances, Pickaxe has at least four — making it much harder to seal off by bombing. Its underground chambers are also thought to offer greater floor space.

As Iran has barred the International Atomic Energy Agency (IAEA) from inspecting the site, most of what is known about Pickaxe comes from open-source leaks and speculation. However, if Iran decided to assemble a nuclear weapon while under attack, this is where they would likely do it. Conventional bombs simply cannot reach it.

Israel's best bunker busters, such as the US-supplied GBU-28, can penetrate up to 6 metres of concrete — nowhere near enough for Pickaxe or even Fordow. "Bunker buster" is a general term for bombs designed to destroy targets located deep underground that conventional bombs cannot reach.

The only weapon that stands a chance is the GBU-57 Massive Ordnance Penetrator, Al Jazeera reports, citing military experts. This 13,000 kg bomb can punch through 61 metres of concrete. It is the most advanced bunker buster in existence, but only the US Air Force can deploy it using the B-2 bomber. Israel does not possess any B-2s.

So, to completely dismantle Iran's nuclear programme, Natanz, Fordow, and Pickaxe would all need to be neutralised — and only the US can pull the trigger, though air power alone may not be sufficient. Special forces would likely be needed on the ground to confirm each site's destruction.

According to Euronews, most of the US refuelling aircraft landed in Italy, Spain and Germany — at bases that typically serve as launch pads for Middle East operations. The Morón Air Base in Spain is one such example. It is a launch site where refueling aircraft take off to serve B-2 bombers in the air, allowing them to continue their mission towards the Middle East.

This suggests the formation of an air corridor designed to sustain a prolonged assault on Iran. There is no need for that level of support in a region where the US already has a substantial presence — unless America is preparing to strike Iran directly, or is setting up a refueling corridor over Iraq or Syria to allow Israeli jets to carry more bombs instead of external fuel tanks.

In the case of a ramp up of aerial assaults, the casualties would be enormous. Already, a mass exodus of civilians is underway, with many fleeing Tehran for safer ground. 

Iran knows the US is likely to join Israel in attacking its nuclear facilities, and thus has prepared its own arsenal for retaliation; the Islamic Republic claims to have developed missiles that can fly hypersonic (non-ballistic) trajectories through the atmosphere, which would make them harder to intercept even by the Iron Dome.

According to Ralph Savelsberg, an associate professor at the Netherlands Defence Academy in Den Helder, specialising in missile defence, to protect its hypersonic missiles against air strikes, for years Iran has been building underground missile facilities.

These missiles are not meant for symbolic retaliation. They are reserved for high-impact, targeted strikes on US military assets across the region if America gets directly involved.

According to defence experts, Iran's strategy could include targets like the British RAF base Akrotiri and the Andreas Papandreou Air Base in Cyprus — both crucial to surveillance and regional operations. Other high-priority targets might include Al Udeid Air Base in Qatar (America's main command hub in the region), the Kadhimiya and Habbaniyah bases in Iraq, Ali Al Salem Air Base and Camp Arifjan in Kuwait, Al Dhafra Air Base in the UAE, Muwaffaq Salti Air Base in Jordan, and Prince Sultan Air Base in Saudi Arabia.

Also within range are US carrier strike groups in the Red Sea and Eastern Mediterranean, and the Naval Support Activity base in Bahrain, which houses the US Fifth Fleet. If Iran fires its hypersonic missiles at these targets, the casualties could be devastating.

However, Tehran understands that if this conflict escalates into a full-scale war, even its most secure sites may not remain safe for long. Which is why it is carefully weighing when, where, and if to use its most powerful weapons.