A dangerous incident occurred on April 15, 2020, between 11 fast-attack craft (FAC) of the Iranian Revolutionary Guard Corps Navy (IRGCN) and a number of American naval ships in the northern Arabian Gulf near Bahrain. The Iranian vessels repeatedly crossed the bows and sterns of the U.S. vessels at extremely close range and high speeds, with one coming within 10 yards of a U.S. ship.

These actions were in blatant violation of the International Regulations for Preventing Collisions at Sea (COLREGS) and other international agreements relating to the security of vessels.

The Iranian action was aimed at testing the readiness and response of the American naval forces. In response, the American forces practiced their combat doctrine for dealing with swarming attacks by various types of  Iranian fast-attack craft. These FAC could be manned or could serve as unmanned bomb boats. Some of them are equipped with rockets.

This incident occurred after a relatively long period in which the Iranians abstained from provoking the American naval forces operating in the area, after the U.S. had issued stern warnings to Iran against such incidents. This incident appears to be a sign that Iran is prepared to escalate its hostile actions against the U.S. and its allies.

Earlier in the vital Strait of Hormuz, on March 27, two boats approached a U.S.-flagged container ship, while Revolutionary Guard FAC approached a ship on April 2. On April 13, armed men boarded the Hong Kong-flagged SC Taipei bound for Saudi Arabia, near Iran’s Ras al-Kuh coast, holding the ship for a short time before releasing it. The Revolutionary Guard Navy was probably responsible for the incident.

The Iranian Revolutionary Guard Corps Navy, with more than 20,000 servicemen, is considered one of the key forces to defend Iran’s maritime borders. It has trained for years in asymmetrical warfare against American forces, concentrating its efforts on fielding hundreds of fast-attack craft against the Americans, as well as commando attacks and ground-to-sea rocket attacks. It has also trained to lay mines against U.S. ships and its naval bases in the Gulf States.

The Revolutionary Guard Navy, operating from a number of bases along the coast of the Persian Gulf, was also involved in attacks on Saudi oil tankers in May 2019. Their involvement was revealed by American intelligence which photographed the Iranians as they placed mines on the tankers. Iranian media reported recently that Fajr-5 rocket batteries (333 mm., range 75 km.) have been deployed along the Strait of Hormuz coastline.