The deployment of about 2,500 U.S. Marines to the Middle East marks a new phase in the conflict with Iran, which is now in its second week. The move comes at a time when Iranian forces are intensifying their activity in the Strait of Hormuz, one of the world's most important energy transport corridors. According to two Pentagon officials quoted by The New York Times, the unit that will be deployed to the region is the 31st Marine Expeditionary Unit.
The deployment of the unit comes as the US Department of Defense grapples with the possibility that Iranian forces could lay naval mines in the Strait of Hormuz, a narrow passage through which about a fifth of the world's oil supplies pass. US airstrikes have reportedly forced Iranian forces to withdraw their large warships and instead use smaller, faster craft that can carry mines and more easily evade aircraft. The craft are believed to operate from islands near the strait.
With the arrival of the 31st Marine Expeditionary Unit from the Indo-Pacific region in the coming days, the Pentagon could conduct rapid operations on these islands, using Marine units with air and logistical support, according to a former senior US Defense Department official. The development increases the risk of escalating the conflict. US President Donald Trump has previously authorized smaller-scale military operations, such as the January operation to capture Venezuelan President Nicolás Maduro. On Friday, Trump announced on social media that the US military had carried out a major airstrike on the island of Kharg Island, a key port and main hub for Iranian oil exports. According to him, the operation “completely neutralized” military forces on the island, while emphasizing that he had instructed the Pentagon not to strike oil facilities.
Meanwhile, international oil prices have increased by about 40% since the start of military operations against Iran by the United States and Israel late last month.
The role of the Marines in the region
Although the number of Marines is relatively small compared to the approximately 50 US troops already in the region, the Marine Expeditionary Units are considered very valuable by military commanders, as they can quickly deploy forces and equipment on the ground. In the Strait of Hormuz, the Marines can also undertake anti-drone operations using electronic jamming systems on their ships, as well as escort tankers and other commercial vessels.
Expeditionary units typically operate from several warships, including amphibious assault ships carrying MV-22 Osprey aircraft, transport helicopters, and fighter jets such as the F-35 Lightning II. However, the force’s relocation from its base in Okinawa, Japan, creates a gap in the U.S. rapid response capability in the Pacific region, including sensitive areas such as South Korea and Taiwan. Historically, Marine expeditionary units — often called “America’s 9-1-1 force” — have been used in war zones, embassy evacuations, and counter-piracy missions. Marines from the 15th Marine Expeditionary Unit were among the first U.S. forces on the ground during the U.S. invasion of Afghanistan in 2001.
