Dzirhan Mahadzir – June 29, 2026 11:56 AM
Decommissioned amphibious transport dock USS Juneau (LPD-10) was sunk by the U.S. and partner nations on Saturday in the Philippine Sea during the ongoing Valiant Shield 2026 exercise.
Juneau was sunk more than 200 nautical miles off the coast in the Mariana Islands Range Complex during a sinking exercise that brought together air, surface and subsurface assets for coordinated strikes. The ship entered service in 1969 and saw action in the Vietnam War and Operation Desert Storm before decommissioning in 2008.
“This SINKEX provided an outstanding opportunity for our joint team to integrate capabilities across domains, honing the lethal precision and coordination essential for high-end maritime operations in the Pacific theater,” said Rear Adm. Eric Anduze, commander of Carrier Strike Group (CSG) 5 and Task Force 70, in a news release.
The release did not identify the forces involved in the exercise. Pentagon images show the final hit that sank Juneau was a torpedo strike from a Japan Maritime Self-Defense Force submarine. Aircraft from the George Washington CSG operated in support of the SINKEX. The George Washington CSG includes aircraft carrier USS George Washington (CVN-73) with embarked Carrier Air Wing (CVW) 5, cruiser USS Robert Smalls (CG-62) and destroyers USS Benfold (DDG-65) and USS Shoup (DDG-86).
A JMSDF SH-60 helicopter fired a AGM-114 Hellfire missile at Juneau and a JMSDF destroyer launched a Type 90 anti-ship missile, according to photos shared Sunday by Japan’s Joint Staff Office.
Earlier during Valiant Shield, an anti-submarine warfare exercise was conducted by the George Washington CSG, JMSDF destroyer carrier JS Kaga (DDH-184) and destroyer JS Fuyuzuki (DD-118), Royal Canadian Navy (RCN) frigate HMCS Charlottetown (FFH339) and P-8A Poseidon Maritime Patrol Aircraft (MPA) from Patrol and Reconnaissance 26, Royal New Zealand Air Force No. 5 Squadron and the Royal Australian Air Force. The allies formed a task group to locate and track submarine USS Minnesota (SSN-783) and JMSDF submarine JS Jingei (SS-515).
Valiant Shield 26 is taking place in the Commonwealth of the Northern Mariana Islands, Guam, Japan and at sea around the Mariana Islands Range Complex. The exercise runs from June 22 to Wednesday. Valiant Shield is a multinational, biennial field training exercise focused on integrating interoperability training in a multi-domain environment, according to the U.S. Navy news release.
Meanwhile, U.S. Pacific Fleet submarines will integrate with unmanned undersea vehicles as well as participate in a SINKEX as part of the U.S.-led Rim of the Pacific 2026. RIMPAC kicked off Thursday in Hawaii and will run until July 31 with 31 surface ships, 5 submarines, 197 aircraft and approximately 30,000 personnel including 1100 landing forces from 30 nations taking part in the drills..
RIMPAC 2026 will highlight two critical investments that are meant to reshape how Commander, Submarine Force, U.S. Pacific Fleet (COMSUBPAC) units train to fight and win in contested maritime environments, namely advanced unmanned undersea vehicles (UUVs) and long-range fires, according to a U.S. Navy news release.
COMSUBPAC units will integrate with UUV capabilities to extend the reach and persistence of undersea intelligence, surveillance and reconnaissance (ISR). These platforms will simulate operating autonomously in denied areas, providing critical targeting data and enhancing the U.S. Navy’s ability to detect, track and hold adversary forces at risk. The demonstration leverages unmanned systems as force multipliers, enabling manned platforms to operate with greater stealth, lethality, and efficiency, according to the release.
“COMSUBPAC is committed to developing UUV capabilities with allies and partners to increase interoperability and to deter aggression throughout the Pacific,” reads the release.
In addition, COMSUBPAC submarines are scheduled to conduct precision long-range fires during RIMPAC 26 using UGM-84 Harpoon anti-ship cruise missiles. The integration of submarine-launched fires in the broader targeting cycle reinforces the critical role of the undersea domain in multi-domain operations, the U.S. Navy said.
“Successfully integrating emerging UUV systems with existing precision strike capabilities and strengthening tactical integration and communication with our undersea warfare (USW) counterparts preserves our combined decisive advantage in the undersea domain,” reads the release.
Five submarines are taking part in RIMPAC 2026. The U.S. Navy will deploy attack submarines USS Charlotte (SSN-766) and USS Columbia (SSN-771) to join the Peruvian Navy’s BAP Chipana (SS-34), the Republic of Korea Navy’s ROKS Dosan Ahn Changho (SS-083) and the Royal Canadian Navy’s HMCS Corner Brook (SSK878).
Dzirhan Mahadzir
Dzirhan Mahadzir is a freelance defense journalist and analyst based in Kuala Lumpur Malaysia. Among the publications he has written for and currently writes for since 1998 includes Defence Review Asia, Jane’s Defence Weekly, Navy International, International Defence Review, Asian Defence Journal, Defence Helicopter, Asian Military Review and the Asia-Pacific Defence Reporter.