By Mark Pyruz

IRIS Jamaran (76) and IRIS Alborz (72)
At his latest press conference, President Ahmadinejad today warned that any inspections of its ships related to sanctions could provoke a response by the Islamic Republic of Iran.
"If they make the slightest mistake we will definitely respond," Ahmadinejad said.
Some observers have criticized Iran's naval forces for being relatively weak in overall strength, particularly when compared to the US Navy Fifth Fleet in the Persian Gulf waters. They also point out Iran's naval forces are less than state of the art. But these naval forces, while relatively small and somewhat under-equipped, are adequately suited for selectively targeted merchant shipping interdiction, including boarding, inspection and search of a ship at sea; second, taking measures including any combination of arresting the vessel, arresting persons aboard or seizing cargo.
Naval vessels and armed forces of the Islamic Republic of Iran Navy (IRIN) in the Persian Gulf and Gulf of Oman, and the Islamic Revolutionary Guard Corps Navy (IRGCN) in the Persian Gulf, are able to conduct such operations. These include the Alvand class frigates, Moudge class frigate and Thondar class missile crafts.

Lineup of four IRGCN Thondar class missile craft
Of course, such actions are extremely risky for the Islamic Republic, as escalation could quickly follow. However, the same risks apply to the United States, which could lead to a cascading of events resulting in the breakout of open hostilities. Just the temporary stoppage or seizure of a merchant ship by Iranian naval forces, alone, particularly near the Straight of Hormuz, could lead to a dramatic spike in shipping insurance rates and the price of crude oil. It would likely even prompt some form of active USN escort coverage.
The previous round of sanctions technically called for a potential inspection regimen of "suspected" Iranian related shipping, but it was not acted upon in a meaningful or provocative manner. The ball is again in the court of the United States, on whether or not we'll see such a turn of events associated with this latest round of sanctioning.

Trio of Kaman class (Combattante IIB type) missile boats