Written by Yoel Guzansky
INSS Insight No. 204,
Iran’s oft-sounded threats to close the Straits of Hormuz to international shipping and thereby stop the flow of Gulf oil seem to have increased in frequency and intensity, apparently in light of the decision to impose harsher sanctions against Iran. Senior Iranian officials have thus warned that “any act of aggression or adventure” – in practice this means inspections of cargoes of Iranian ships (a step included in the Security Council resolution on
In general, these pronouncements are designed to deter the international community from fulfilling its resolutions and raise the cost of any military confrontation with
The Straits of Hormuz are considered one of the most important naval passages in the world, and any interference to the flow of oil through them would immediately affect the global energy market. An overwhelming majority of the Gulf’s oil exports – some 90 percent – go through the Straits. The American Energy Department estimates that some 17 million barrels of oil – 20-30 percent of global consumption – pass through the Straits daily, in addition to 20 percent of the world liquid natural gas transports. Every day, some 15 tankers make their way through the Straits, most of which are headed for the Asian markets (e.g., over 75 percent of
The oil moves in tankers through the Straits, whose narrowest point is
Even in the unlikely possibility that Iran could seal the Straits hermetically over a long period of time, such a move is not in Iran’s own best interests, as it would interfere with the import of refined oil to Iran and Iran’s export of crude oil (representing some 80 percent of its income) and would almost certainly lead to a confrontation with the American navy. Therefore,
Because of the Iranian navy’s weakness and America’s military superiority in the Gulf, Iran has placed priority on acquiring and building a large number of small, fast-moving vessels (some of which are for unmanned use) and has re-outfitted civilian vessels for military missions. As a result, in recent years there have been reports of Revolutionary Guard naval vessels skirmishing with American vessels. In January 2008, Iranian boats approached American vessels in a threatening manner, using the so-called swarm tactic: many small, fast-moving boats, some laden with explosives, intend to attack the target simultaneously from different directions (together with support from air and land fire) in order to stun the enemy’s defensive systems and limit the enemy’s capacity for responding effectively.
Recent assessments indicated that the American 5th Fleet is capable of opening the Straits to naval vessels within a week. Such assessments may be based on the fundamental weakness of the Iranian air force, a belief in the American capability of paralyzing Iranian positions near the Straits, the
Moreover, new Iranian means and improved tactics may present a more significant challenge to the American navy. As early as 2008,
Any American attempt to open the Straits would require at least partial removal of naval mine fields and dealing with the Iranian shore-to-sea missiles. Moreover, since such a confrontation is liable to develop into a more widespread campaign, questions arise regarding the West’s ability to limit the confrontation in time and space. For example, it may be that in tandem with an Iranian blockade of the Straits there would be an attack on the western shore of the Gulf, where there are strategic infrastructure facilities such as ports, refineries, and desalination plants.
Even in a more optimistic scenario (a partial blockade of the Straits with rapid, effective international action to open them), the impact of a “limited” campaign on the global energy market is liable to last a long time, beyond the event itself, because of the concern about a lack of supply. A longer event might necessitate the use of strategic reserves, taking advantage of the redundancy of global manufacturing capabilities (greatly limited because it is primarily concentrated in the Gulf region) and using alternate shipping routes such as the Saudi pipeline moving oil from the Gulf to the Red Sea (5 million barrels per day) and the Habshan-Fujairah pipeline, which is supposed to start operating next year and ferry 1.5 million barrels per day from the Gulf daily.
The Iranians apparently prefer to focus on harassment, i.e., pinpoint systematic attacks while attempting to cover up their responsibility for the events (e.g., by using civilian platforms or by acting outside of their own territorial waters). Because of its fundamental military weakness,