The US Navy’s remaining Avenger-class minesweepers took part in the recent exercises, but the most advanced Littoral Combat Ships did not—probably because they were needed in the Persian Gulf.

Sea mines remain a critical and asymmetric strategic threat, one capable of paralyzing major shipping lanes, blockading island nations, and even overwhelming allied naval forces. China’s People’s Liberation Army Navy (PLAN) is estimated to hold around 100,000 naval mines in reserve, ranging from traditional contact and moored mines to sophisticated “smart” mines and even rocket-propelled deep-water weapons.

These mines are a core component of China’s so-called “Assassin’s Mace” asymmetric warfare strategy, designed to allow a technologically inferior force to neutralize a superior adversary. The maritime ordnance could be employed across the Indo-Pacific to enforce blockades, deny maritime space, and restrict freedom of movement around Taiwan, the South China Sea, and the First Island Chain.

The other danger is that naval mines are inexpensive to produce and very easy to deploy. Conversely, the effort to clear sea mines takes substantial effort—by some analyses, up to 200 times longer than it takes to lay them!

The US Navy understands the risks that these mines pose. This month, alongside the Republic of Korea (ROK) Navy, it led the ninth Multi-National Mine Warfare Exercise 2026 (MNMIWEX 26) off the southeastern coast of Busan, South Korea. A total of 15 other nations also participated in the multi-day exercises, which brought together a variety of surface mine countermeasures vessels, expeditionary explosive ordnance disposal (EOD) technicians, clearance diving teams, and deployable autonomous underwater vehicle (AUV) detachments.

Working together in the drills, the various elements honed their mine warfare tactics and bolstered interoperability across the maritime domain. In addition to the time on the water, MNMIWEX featured a shore phase, the Multilateral Mine Warfare Symposium, where subject matter experts from the participating nations exchanged ideas on how to counter the maritime threat.

This Sea Is Mine

During the MNMIWEX 26, one of the US Navy’s four remaining forward-deployed Avenger-class mine countermeasures ships, the USS Chief (MCM-14), was dispatched from Sasebo, Japan, to operate under Commander, Task Force 77 (CTF-77), operating with expeditionary mine countermeasures companies and diving detachments from CTF-75 (EOD Mobile Unit 5). The ROK Navy deployed mine-laying and hunting vessels from its Mine Warfare and Salvage Flotilla 52, which was further supported by specialized expeditionary clearance divers and underwater disposal teams from the ROK Navy Sea Salvage and Rescue Unit (SSU).

Among the allied and partner nations that took part in the joint exercise were ships and/or personnel from Brazil, Canada, Colombia, Indonesia, Italy, Japan, Malaysia, Oman, the Philippines, Singapore, and Thailand.

 “It is always an honor and a privilege to work with our partners and continue to build on our powerful relationships in the Mine Countermeasures community,” said US Navy Capt. G. Scott Wells, Commander Task Force Seven-Seven. “We are proud to have participated in another successful multi-national interoperability event with our allies and partners, further increasing our MCM capacity and strengthening our overall capabilities.”

According to the sea service, the exercise included “integrated mine-hunting evolutions, harbor clearance and port break-in scenarios, shallow-water explosive ordnance disposal, and seabed surveys using unmanned underwater systems” conducted by the combined forces.

“Through this Multilateral Mine Warfare Symposium, we were able to share operational experience and know-how with participating nations, reaffirming the importance of multi-lateral cooperation,” said Capt. Lee Geun-rok, 52nd Mine Warfare Squadron Commodore of the ROK Navy. “In the Multi-lateral Mine Warfare Exercise, we applied the strategic discussions from the symposium into the practical training, utilizing it as an opportunity to substantially enhance interoperability and combined operational execution capability in the field of mine warfare.”

Why Didn’t the US Navy Bring Its Littoral Combat Ships?

It is unclear why the US Navy didn’t send any Independence­-class Littoral Combat Ships (LCS) equipped with the Mine Countermeasure (MCM) Mission Package to take part in MNMIWEX 26. The only reason may be that the LCS equipped with the MCM modules—the USS Canberra (LCS-30), the USS Tulsa (LCS-16), and the USS Santa Barbara (LCS-32)—remain committed to the US Navy’s Fifth Fleet in Bahrain. Following the decommissioning of the Avenger-class mine countermeasure ships based in the Middle East in late 2025, the LCSes have become the primary “shield” tasked with maintaining real-world maritime security in the volatile Strait of Hormuz.

Still, the MCM Package operates far differently from the older Avenger class. The newer LCS equipped with the MCM Mission Package hunts for mines using a fundamentally off-board, remote, and autonomous approach, whereas the legacy Avenger-class minesweepers relied heavily on direct hull-mounted systems and physical or close-in operations. (The Avenger-class vessels are built from wood and fiberglass instead of metal, allowing for relatively safe operations near metal-sensitive mines.) The MCM Package utilizes an Unmanned Surface Vehicle (USV) towing an AN/AQS-20 sonar system. In addition, MH-60S helicopters operating from the LCS are equipped with the Airborne Laser Mine Detection System (ALMDS).

The US Navy plans to eventually employ 15 Independence-class LCSes with the MCM package. Over time, these will replace the service’s 14 remaining Avenger-class vessels, of which just four remain in active service today. The last four ships that were operating out of Bahrain—the USS Devastator (MCM-6), the USS Dextrous (MCM-13), the USS Gladiator (MCM-11), and the USS Sentry (MCM-3)—were decommissioned in September 2025 and transported back to the United States in early 2026 for eventual scrapping.

About the Author: Peter Suciu

Peter Suciu has contributed to dozens of newspapers, magazines, and websites over a 30-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, politics, and international affairs. Peter is also a contributing writer for Forbes and Clearance Jobs. He is based in Michigan. You can follow him on Twitter: @PeterSuciu. You can email the author at Editor@nationalinterest.org.

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