Iran plays naval cat-and-mouse game in the Gulf
Western military protection for its tankers is expanding, but unconventional tactics remain a threat
The arrival of a second British warship in the Gulf on 28 July means London has the resources to escort UK-flagged vessels through the Strait of Hormuz. But this support will be small comfort to tanker captains, or the industry that depends on them.
State-of-the-art destroyer HMS Duncan and the already Gulf-based frigate HMS Montrose have the firepower, if backed by planes from the US 5th Fleet, to counter Iran's ageing collection of conventional bombers, frigates and submarines. But Iran has several unconventional means of causing havoc if it chooses.
Limpet mines, placed by frogmen or delivered by fast boats, have already struck six tankers in the Gulf of Oman, triggering a blame-game about who is responsible. Tehran has issued emphatic denials, while Washington produced a video it says shows an Iranian fast boast removing an unexploded limpet mine from the Japanese-owned Kokura Courageous in June.
One attraction of deploying mines is their deniability. Another is the fact that the Strait of Hormuz is just 21 nautical miles wide at its narrowest point, and such tight shipping channels make it vulnerable to anti-shipping mines. Britain anticipated the problem some years ago; since 2015 it has based four minesweepers in Bahrain that are capable of keeping shipping lanes clear, provided the lanes are not also under attack by conventional means.
Small distances mean reaction times are tight, requiring quick decision-making from escort captains
Iran also has anti-shipping missiles and the small distances across the Gulf means they can be deployed on land and remain undetectable until fired.
Another potent threat in Iran's arsenal is the so-called swarm tactics of its fleet of armed speed boats deployed by the Revolutionary Guard, a parallel military organisation to its regular forces. The Guard has several hundred such boats, equipped with machine guns and rockets.
The military situation is broadly the same as during the Tanker War of 1984-88, when Iran, at war with Iraq, targeted Kuwaiti oil tankers carrying Iraqi oil. Kuwait reflagged its tankers as American, gaining US navy protection, but the result was chaotic. Two US warships were hit, one in error by Iraq, along with several Iranian ships and oil platforms. During one melee in 1988, an Iranian airliner was accidentally shot down by a US warship with the loss of 260 lives. While technology has advanced since the 1980s, the strategic equation has not; if fighting breaks out, Iran has the initiative.
The UK has not published its rules of engagement in the Gulf, but London's tactic is for escort ships to trail tankers through the Strait, allowing the warship to accelerate to block the path of Iranian speed boats. Early in July, HMS Montrose trained its guns on Iranian speed boats as they approached a tanker. The small distances mean reaction times are tight, requiring quick decision-making from escort captains.
A complicating factor is that the Gulf is home to three separate but linked crises. One is the seizure of Stena Impero by Iran in retaliation for the British seizure in Gibraltar of its tanker Grace 1 in early July. Second is the Iran-US standoff triggered by the Trump administration's imposition of sanctions on Tehran in May. Third is the blockade, now into its third year, of Qatar by Saudi Arabia and the United Arab Emirates, all three allies of the US and two (Saudi Arabia and the UAE) staunch adversaries of Iran.
Optimists among military planners think Iran will not close the Strait because it would cut off its own oil exports. But those exports have plunged since the US imposed sanctions, from 2.5mn bl/d in April to an estimated 100,000bl/d in July. At this level, Tehran may decide it has little to lose, and much to gain, by upping the military ante.
Source: Petroleum Economist