U.S. can prevent Iran from closing Straits of Hormuz

In a study conducted for NPEC by energy researchers at Rice University, two key vulnerabilities in the Gulf oil production and distribution system in Saudi Arabia were identified. The first is an Iranian threat to close the Straits of Hormuz. Such a threat, Rice analysts argue, could be significantly reduced by upgrading and complementing the trans-Saudi Arabian Petroline, which would allow 11 million barrels a day to be shipped to ports on the Red Sea. This could be done with technical upgrades to the trans-Saudi Arabian line and by bringing the Iraqi-Saudi pipeline (Ipsa–2) back on line. To do the latter would require an agreement with Baghdad. The cost of the entire project is estimated to be $600 million. Assuming the worst -- a complete closure of the Straits of Hormuz -- this bypass system is estimated to be capable of reducing the economic impact on the U.S. to a loss of only 1 percent of gross domestic product. This figure could be reduced even further if additional pipelines were built from Abu Dhabi to ports in Oman. There are a number of ways in which these projects could be financed. Given the high price of oil and the large revenue streams high prices are now generating, the best time to finance such construction is now.

Most of these countries rely on the safe transport of oil through one 21-mile-wide waterway: the Strait of Hormuz, which leads out of the Persian Gulf into the Indian Ocean and through which 16.5-17.0 million barrels of oil were shipped daily in 2004 (accounting for nearly 25 percent of global oil shipments). Oil bound for China, Japan, and the West Coast of the United States from the Middle East must also transit the Strait of Malacca and the Strait of Singapore, both of which carried 11.7 million barrels per day in 2004. These passageways are the chokepoints where the potential for the disruption of tanker traffic by terrorist attacks or naval blockades is greatest.But in reality the risks to maritime flows of oil are far smaller than is commonly assumed. First, tankers are much less vulnerable than conventional wisdom holds. Second, limited regional conflicts would be unlikely to seriously upset traffic, and terrorist attacks against shipping would have even less of an economic effect. Third, only a naval power of the United States' strength could seriously disrupt oil shipments, but the United States is more likely to protect shipping on the high seas than to do anything to endanger it. Fourth, if any country attempted to interfere with international shipping, a coalition would inevitably form to keep traffic flowing with manageable damage to oil deliveries and the global economy. Finally, although all-out wars between major powers can seriously disrupt maritime shipping, the chances of such a conflict happening in the foreseeable future are remote.

The greater number of tankers traveling at higher speeds and in more congested shipping lanes makes it increasingly difficult to identify and intercept them. This is especially true for submarines, which have a limited ability to identify surface ships and have only a small onboard supply of torpedoes and antiship missiles. If a submarine attacks a ship using just two torpedoes, it will have exhausted more than a tenth of its standard arsenal. Meanwhile, other potential targets nearby will disperse, forcing the submarine to relocate. A single conventional-power submarine (Iran has only three) facing no opposition could realistically expect to damage about half a dozen oil tankers in a busy sea-lane several hundred miles wide over the course of a month, disrupting at most a tiny fraction of the oil deliveries made during that period. Conventional-power submarines, moreover, are relatively slow and cannot catch modern tankers, which travel at 15-20 knots.

It would be challenging, though not impossible, for Iran to use its submarines for mine laying in the strait, due to several factors. First, the underwater geography of the strait neutralizes many of the characteristic advantages of submarines. Kilos require a minimum operating depth of 45 meters, and only in a few places is the water in the strait more than 80 meters deep, limiting the use of tactics such as diving for concealment or protection. Additionally, the high salt content of gulf waters and other factors create heat currents that disturb sonar. As a result, it is harder for submarines to use passive sonar to detect ships without revealing their own location. Submarines become hidden but irrelevant platforms, or useful platforms that are easier to find. Either way, antisubmarine warfare forces gain an advantage, and U.S. ASW patrols in the gulf would be likely to detect mine-laying activity by Iranian submarines. There is evidence Iran may have realized these problems and is planning to relocate its submarines to the Gulf of Oman.