The Pentagon realizes the Strait is vulnerable. “‘The simple answer is yes, they can block it,’” stated Chairman of the Joint Chiefs of Staff General Martin Dempsey on January 8, 2012.34 For the past twenty years, Iran has invested heavily in the asymmetric capabilities needed to bypass the more powerful U.S. fleet and disrupt merchant shipping and threaten naval forces in the Strait. Iran has concentrated on acquiring naval mines, fleets of heavily armed speedboats, and powerful anti-ship cruise missiles, secret- ly situated along the bottleneck.
The regular Iranian Navy is relatively professional, and it operates an aging conventional surface fleet that is the remnant of the Shah’s constabu- lary force. The more politically favored and far less predictable Iranian Revolutionary Guard Corps Navy (IRGCN), however, is the country’s guerilla force at sea. The IRGCN has responsibility for security in the Strait of Hormuz, and since the early-1990s, it has invested heavily to keep U.S. forces off balance.35 The highly ideological IRGCN has 20,000 personnel and 5,000 Revolutionary Guard Marines.36 These forces regularly exercise war plans to close the Strait. The force operates from bases at Bandar Abbas and Qeshm along the Strait, practicing small boat swarm exercises against international shipping traffic with as many as forty boats.37
Iran’s naval inventory includes cruise missiles (generally first generation Chinese copies of the French Exocet missile and the indigenous Nasr missile), marine mines, Kilo- and Yono-class submarines, and Peykaap fast attack craft, the latter of which are armed with cruise missiles and torpe- does. These proxy forces are dispersed and mobile, and have mastered swarm techniques to overwhelm more powerful foes. More than a decade ago, a classified Department of Defense war game concluded that agile swarms of IRGCN speedboats could inflict major damage on the U.S. Navy’s powerful warships in a conflict. In the game, the United States lost sixteen major warships, including an aircraft carrier, to swarms of enemy speedboats.38