US quietly prepares for naval clash with Iran in Strait of Hormuz

Iran is ramping up its production of mini-submarines, which are 'a huge problem' for US naval power. The US has countered by sending minesweepers to the region.

Iranian submarines participate in a naval parade on the last day of a war game in the Sea of Oman near the Strait of Hormuz earlier this year.

Iran’s mini-submarines and Special Forces “frogmen” spell trouble for the US Navy

The Iranian military has a growing fleet of mini-submarines that is particularly difficult for the US Navy to detect and track. They are kitted out with torpedoes, highly-trained SEAL-like frogmen, and – most troublesome for the US military – mines that could threaten to shut down the vital Strait of Hormuz shipping lane.

In response, the commander of US forces in the region recently announced that the Navy would be doubling the number of its US minesweepers in the Gulf. The ranks of these minesweepers had remained steady for the past decade, but have risen from four to eight since June.

The ramped-up Iranian production of mini-submarines – as well as the Pentagon’s response – threatens to ratchet up military tensions in the region, analysts say.

The additional four Avenger-class minesweepers arrived in Bahrain on June 24. Along with the minesweepers, the Navy also sent additional minesweeping helicopters called “Sea Dragons.”

Their mission will be to counter the Iranian mini-submarines, which are “a huge problem for us,” says retired Navy Cmdr. Christopher Harmer, who from 2008 to 2009 was the director of future operations for the US Navy Fifth Fleet, stationed in Bahrain.

“They are a threat to us because they can disperse them throughout the Persian Gulf and the Arabian Sea, and it’s extremely difficult for us to track them,” he adds. As a result, they can lay "in wait to execute an ambush.”

The challenge of mini-subs

The US Navy is more accustomed to tracking large, Soviet-era nuclear-class submarines – something Iran knows well, adds Commander Harmer. “Looking for small subs in shallow water is much more difficult, because the acoustics are so much more difficult – smaller makes less noise.”

As a result, he adds, the Iranian military-industrial complex “has prioritized these mini-subs – and have gone into overdrive building them.” Mini-submarines are generally considered any submarine vessel under 500 tons and roughly 100 feet long or less.

Five years ago, the Iranian military had “no mini-subs,” says Harmer, senior naval analyst at the Institute for the Study of War in Washington. Now they have 19 in service, and are building an average of four per year – a “strategically significant” force, he adds.