One of the things Iran has threatened to respond in "many ways" should the European Union refer its nuclear program to the Security Council. While the report of this threat indicated that Iran would cut back oil production, it also should be noted that Iran could decide to try to close the Strait of Hormuz, hoping to force the world to back off in the face of a threat to the flow of oil from the Persian Gulf.
A straight fight with the United States is out of the question for Iran, due to the fact that Iran cannot hope to win one. In April 1988, American and Iranian naval forces engaged in a series of sharp actions after the frigate Samuel B. Roberts was struck by an Iranian mine. Iran has recently bought more modern weapons from Russia (MiG-29 fighters and three Kilo-class diesel-electric submarines) and China (C-802 anti-ship missiles retro-fitted to three Saam-class frigates and ten Kaman-class patrol craft and ten Houdong-class patrol craft for the Revolutionary Guards, C-801 missiles for shore launches, and numerous Silkworm anti-ship missiles). Iran could also lay mines - this latter approach is the most likely to damage an American vessel, and has the benefit of being deniable. However, mining operations are not without risk, as was demonstrated by the capture of the Iran ship Ajr in 1987 (after it was caught heaving mines into the water). Furthermore, in a period where tensions are already high, such an incident could lead to an American preemption. Suicide operations (using aircraft or small speedboats like the Boghammer) are another option which could be effective. The only problem is that they would lack the deniability of mining, and thereby draw a very strong response from the United States.
The United States can bring overwhelming combat power against Iran's newly modernized force. A carrier battle group, supported by submarines, could quickly place Iran's navy on the bottom. Even Iranian mines could be countered relatively quickly, because of the basing of two Osprey-class coastal minesweepers in Bahrain. Additional minesweeping craft would have to come from the United States, but this is much more capability than was present in the late 1980s. In a naval-air confrontation, one carrier battle group of the United States has a huge advantage against the Iranian military.
While Iran has added new capabilities, the United States has not stood still. Any attempt by Iran to shut down the Strait of Hormuz will end in a naval-air confrontation that will probably end with most of Iran's acquisitions from China and Russia on the bottom of the Strait of Hormuz. - Harold C. Hutchison (email@example.com)
The Strait of Hormuz has been a hot spot in the past, most notably during the later stages of the Iran-Iraq War, and is one area that probably occupies the mind of American military planners. It's no surprise, since a lot of maritime traffic (particularly supertankers) goes through that famous chokepoint. One of the countries alongside that chokepoint is Iran, which has been in the news lately.