TEHRAN, Dec. 3 (UPI) -- As tensions with Iran rise again, the Islamic Republic is reported to be expanding its naval power in the oil-rich Gulf and the Arabian Sea to be able to command the chokepoint Strait of Hormuz, the only way in or out of the Gulf.
Closing that strategic waterway to maritime traffic, especially the 15 or so supertankers that sail through it every day delivering the world's oil supplies, would trigger an economic crisis that could cripple the painful efforts to recover from the global financial meltdown of 2008.
The U.S. Office of Naval Intelligence reported in a recent study that came to light a few days ago that overall operational control of naval and coastal missile forces in the region is now in the hands of the increasingly powerful Islamic Revolutionary Guard Corps., which has its own naval arm.
Tehran has threatened to close the Strait of Hormuz if Iran comes under attack by U.S. or Israeli forces over its nuclear program. That would cut off some 40 percent of the world's oil supplies.
According to the naval study, the Revolutionary Guards have expanded their naval capabilities in recent years with ships and technology from China, North Korea and Italy and now deploy some of the fastest naval vessels in the region.
On July 29, Rear Adm. Haibollah Sayyari, commander of Iran's regular navy, which now has responsibility for operations in the Arabian Sea east of the Strait of Hormuz, said the Islamic Republic will stage a stronger presence on the high seas "in a bid to maintain the country's might."
According to the semiofficial Fars News Agency, Sayyari made the announcement when he inaugurated a new jetty for naval speedboats and a military airfield at the Jask naval base on the Gulf of Oman at the eastern approaches to the Strait of Hormuz.
This was just one of several bases the Iranians have expanded or built in the last two or three years along the eastern shore of the Gulf, which Iran controls from the Strait of Hormuz all the way to Iraq's narrow outlet to the sea in the northern end of the waterway.
Iran also controls several small but strategic islands that dominate the shipping lanes in the southern waters of the Gulf.
Batteries of anti-ship missiles, primarily Chinese-designed C-801 and C-802 missiles, have been deployed on these islands that could be used to block the strait.
But sea mines are seen as the most potent threat to shipping, and the Iranians are believed to have a significant number of these in their arsenal.
"The real nuclear option for Iran does not involve nuclear weapons," Texas-based global security consultancy Stratfor noted in a recent assessment of the Iranian threat.
"It would involve mining the Strait of Hormuz and the narrow navigation channels that make up the Persian Gulf."
Iran used mines extensively during the 1980-88 war with Iraq, with both sides attacking oil tankers to throttle each other's economies.
That sent oil prices and insurance rates soaring. But the strait was never closed and shipping activity continued.
If the strait was closed, or threatened enough to curtail shipping, the economic consequences would be immense.
The impact, Stratfor observed, "would be immediate and dramatic. The nastiest part of the equation would be that in mine warfare it is very hard to know when all the mines have been cleared. …
"There is possibility that the strait could be effectively closed to supertankers for a considerable period. The effect on oil prices would be severe."
But it is the danger of precipitating just such an economic crisis that is a principal reason why Western analysts believe Israel is unlikely to unleash threatened pre-emptive air and missile strikes against Iran's nuclear infrastructure.
Iran would respond by trying to close the strait, even though it depends on the waterway as much as everyone else.
Israel "would be held responsible for a potentially disastrous oil shortage," Stratfor noted.
"Only the Americans have the resources to even consider dealing with the potential Iranian response, because only the Americans have the possibility of keeping Persian Gulf shipping open once the shooting starts."