Iran's Threat to the Strait of Hormuz

Could Iran close international access to the Persian Gulf, in the event of American or Israeli strikes on Tehran's nuclear program, causing a potentially catastrophic decline in available world petroleum supplies?

The possibility of this conflict scenario is examined by Caitlin Talmadge, in "Closing Time: Assessing the Iranian Threat to the Strait of Hormuz."

The article's particularly timely.

Just last weekend OPEC oil ministers warned that global oil prices could skyrocket in the event of a U.S. or Israeli attack on Iran, and with the oil price-per-barrel currently at record highs, Western vulnerability to economic blowback is acute. Further, some commentators in the press have recently reported details of clandestine planning - at the highest levels of the U.S. government - for a preventive attack on Iran's nuclear program. Behind all of this, some allege, is the drumbeat for war among small but influential sections of the American foreign policy communtity.

Talmadge's piece is comprehensive yet balanced, and suggests that Iran - while rudimentary on many indices - possesses considerable military assets that make the potential for a 21-century Dardanelles crisis not unthinkable.

Here's the introduction:

Iranian closure of the Strait of Hormuz tops the list of global energy security nightmares. Roughly 90 percent of all Persian Gulf oil leaves the region on tankers that must pass through this narrow waterway opposite the Iranian coast, and land pipelines do not provide sufficient alternative export routes. Extended closure of the strait would remove roughly a quarter of the world’s oil from the market, causing a supply shock of the type not seen since the glory days of OPEC. Even if the strait were not closed in the sense of being physically barricaded, military conflict in the area could cause prices to skyrocket in anticipation of a supply disruption—and to remain high until markets could be assured that the flow of commerce had been restored. Consider that when Iraq invaded Kuwait in 1990, temporarily halting the export of oil in both countries, the world price of oil more than doubled merely on the expectation of future shortages. Although excess global supply combined with increased Saudi production helped lower the price within a few months, it did not return to the preinvasion level for nearly a year. Blockage of the strait would pose a vastly greater threat to the flow of gulf oil, and at a time when excess global capacity is lower and the price of oil higher.

Yet could Iran close the Strait of Hormuz? What might provoke Iran to take an action so contrary to its own economic interests? Does Iran possess the military assets needed to engage in a campaign in the strait, and what might such a campaign look like? Perhaps more important, what would the U.S. military have to do to defend the strait in the event of Iranian interference there? What would be the likely cost, length, and outcome of such efforts?

Despite consensus on the importance of the strait, no open-source analysis has attempted to answer these questions systematically. Some analysts take the Iranian ability to block the strait as a given, whereas others are equally confident the United States’ military superiority would deter or quickly end any Iranian campaign. One observer argues that “countering any Iranian blockade might involve only a few days of fighting, with major disruption to shipping lasting only slightly longer.” Another warns that the United States might have to engage in weeks or months of military operations to open and defend the strait. Anthony Cordesman, a highly respected expert on the Persian Gulf, concludes that “Iran could not ‘close the Gulf’ for more than a few days to two weeks,” although what leads him to this conclusion is unclear. Meanwhile, the director of the Defense Intelligence Agency, Vice Adm. Lowell Jacoby, testified in 2005 that Iran has some capability to “briefly close” the strait, without defining what “briefly” means. In short, analysts disagree about the potential likelihood, course, and outcome of U.S.-Iranian conflict in the Strait of Hormuz, but the nature of current debate on the subject makes it hard to ascertain the basis of differing assessments, much less determine which might be correct.

Talmadge follows this up with a detailed analysis of the U.S.-Iranian offense/defence balance in open-seas mine warfare, Iranian antiship cruise missile capability and U.S. counter-missile defenses (advanced warning and attack radar systems), and Iranian air- and land-based defenses against U.S. airspace superiority.

Talmadge concludes:

Iran’s limitations, such as the command and control and targeting challenges it would face in littoral warfare, are not often appreciated. But its strengths are often overlooked as well, such as the stocks of missiles and much more explosively powerful mines it has acquired since the tanker wars of the 1980s. Likewise, although the United States retains the world’s best conventional military, its past experiences hunting mobile targets from the air and conducting MCM operations in the littorals do not inspire confidence that confrontation in the strait would end quickly. The United States’ fleet defenses have never been tested in combat against an adversary with large numbers of cruise missiles, and the United States is in the midst of a major transition in its entire concept of MCM operations. Given these realities, sanguine assurances about the course and outcome of military conflict in the strait seem unjustified at best, and dangerous at worst.

A key theme of the research suggests there's little doubt surrounding America's technical and logistical dominance in the event of a U.S.-Iran conflict in the Strait. Yet it's clear, as well, if fighting erupts, should Iran deploy its assets with efficacy and stealth, particularly in mine warfare, the U.S. might be forced to fight a longer and wider campaign to degrage Iranian capabilies and willpower in areas peripheral to the immediate battles at the waterway.

The question for analysts and partisans of both sides (advocates for either sanctions or force) is what are the costs and benefits of existing approaches compared to a more forceful response in the absence of Iranian nuclear developmental restraint?

If there is no acceptable diplomatic endgame, according to this research, a sustained conflict is entirely likely, with implications for the international system that might be very costly indeed.