12th Marine Littoral Regiment Designed to Operate in Contested Maritime Zones

By Peter Ong 

Colonel Peter B. Eltringham, commanding officer of the 12th United States Marine Corps Littoral Regiment (12th MLR) based in Okinawa, Japan, provided media with a briefing and fielded questions on April 8, 2025 regarding 12th MLR’s status, functions, and missions.  

“The MLRs are specifically designed to operate in contested maritime zones. MLRs have approximately 2,000 Marines, smaller than a traditional infantry or artillery regiment, but more mobile and survivable in key maritime terrain,” said Eltringham, who also emphasized the importance working with allied partnerships. 12th MLR has a Littoral Combat Team consisting of infantry and anti-ship battalion, an anti-air battalion, and a logistics battalion. 

Colonel Eltringham said that 3rd MLR is based in Hawaii and works closely with the Philippine Armed Forces whereas 12th MLR works with the Japanese air, land, and sea defense forces. The 3rd MLR has received new systems such as Naval Strike Missiles on unmanned Joint Light Tactical Vehicles (JLTVs to form NMESIS) and Marine Air Defense Integrated System (MADIS, JLTVs with turret mounted 30mm, 7.62mm, and Stinger missiles) whereas the 12th MLR will field those systems in the coming months. 

Colonel Eltringham replied to a question asking how MLR exemplifies Distributed Maritime Operations and lethality. The baseline MLR formations are broken into small, dispersed networks that “provide command and control, sustainment, strike, and sensing assets for the right time and place of our choosing and integrate them with the U.S. Army, Navy, Air Force, and allies.” 

Colonel Eltringham replied to a question asking for examples of Artificial Intelligence and autonomous systems in the 12th MLR. He mentioned the Autonomous Low-Profile Vessel (ALPV) semisubmersible and NMESIS. Another question asked when does testing stop and buying begin in which Eltringham said “technology on the battlefield is moving so quickly. I want to make sure that we are continually experimenting with C2 [command and control] sustainment, strike, and sensing realm.” 

To a question asking how paying for Readiness might hinder modernization, “Readiness absolutely takes up funding…we’ve got to train…deploy…ammunition…all that stuff costs money,” said Eltringham, but NMESIS, MADIS, and ALPV are modernization funding efforts. 

Replying to a question asking for a “WOW!” factor in the MLR since many other nations have made huge breakthroughs in technological advances and drone usage, Colonel Eltringham said that 12th MLR has the ability for multidomain operations across air, land, sea, space, and cyber and brings it down to the colonel level in addition to sharing the information with allies through communications and connectivity. 

Replying to a question asking for the biggest challenge in working with Japan against China, the colonel said it’s being able to operate constantly. 

Another question asked how training NMESIS and MADIS differ, the colonel said that the training methodologies are the same, but the ordnance differs.  

Finally, Eltringham replied to a question on how MLR fights with contested logistics, saying “that involves working locally, working within the environment, having senses, and having jungle warfare training.”