Amphibious Rapid Deployment Brigade [ARDB] / 15th Brigade

Under Japan’s Medium Term Defense Program (2014-FY2018), the Ministry of Defense proposed to transform two GSDF divisions and two brigades into two rapid deployment divisions and two rapid deployment brigades, including an amphibious rapid deployment brigade.

Amphibious assaults against defended positions would be high-risk operationally and politically. The temptation would be to use JSDF amphibious operations to pre-empt escalation by China should it appear that Chinese forces are preparing to seize the Senkaku Islands.

The JGSDF Amphibious Rapid Deployment Brigade [ARDB], established March 27, 2018, is the Japanese government’s concept to deal with various situations on islands. The ARDB combines ground forces, aviation support, and logistical capabilities into a cohesive unit capable of reacting to a variety of scenarios, including self-defense and humanitarian assistance-disaster relief.

Marines and Sailors with Combat Logistics Battalion 31, 31st Marine Expeditionary Unit (MEU), and Japan Ground Self-Defense Force (JGSDF) service members completed training with the newly formed ARDB in Sasebo, Japan, May 24, 2018. The ARDB combines Japanese air, ground and sea forces, similar to a U.S. Marine Corps Marine Air-Ground Task Force. “We have so many challenges and have to improve our capabilities,” said JGSDF Lt. Col. Ken Tsuneda, commanding officer, Logistics Battalion, ARDB. “In this exercise we were able to partner with the Marine Corps and gain knowledge.” The Marines and Sailors observed and gave their advice to the ARDB on how to improve their skills moving forward. The JGSDF service members are excited for the next exercise, according to Tsuneda, “It was a very nice opportunity and the exercise was the first step toward a new partnership.”

Units from the U.S. military and Japan Self Defense Force (JSDF) conducted exercise Keen Sword beginning Oct. 29, 2018. The biennial exercise is the latest in a series of joint/bilateral field training exercises since 1986 designed to increase combat readiness and interoperability of U.S. forces and the JSDF. Two Royal Canadian Navy ships will participate in the maritime portion of the exercise for the first time. This year’s iteration will feature the Japan Ground Self-Defense Force’s (JGSDF) Amphibious Rapid Deployment Brigade (ARDB), which will conduct amphibious landings in the vicinity of Guam and Tinian. U.S. Marines from III Marine Expeditionary Force will work side-by-side with the ARDB and serve as mentors and evaluators.

In December 2018 U.S. Marines with 3D Marine Expeditionary Brigade and soldiers with the Japan Ground Self-Defense Force’s Amphibious Rapid Deployment Brigade spent over a week advancing their operational capabilities, interoperability and partnership through exercise Yama Sakura 75 on Camp Courtney, Okinawa, Japan. Yama Sakura enhanced the alliance and interoperability between U.S. and Japanese forces and allowed them to plan and execute amphibious operations together in the construct of a computer simulation. Yama Sakura 75 marked the second exercise in 2018 when 3D MEB partnered with the ARDB, which stood up in 2018 in order to advance the JGSDF’s amphibious capabilities.

The GSDF's 1st Combined Brigade, based in Naha, has been upgraded and reorganized as the 15th Brigade. On 26 March 2010, a ceremony was held to mark the brigade's upgrading at the GSDF's Camp Naha, which faces the East China Sea. The Ground Self-Defense Force's upgrading of the Naha-based GSDF brigade can be seen as a first step toward countering China's attempt to expand its sphere of influence in the East China Sea through its military buildup. The 15th Brigade has about 2,100 troops, an increase of about 300 from the 1st Combined Brigade. The new brigade incorporates an infantry regiment comprising three companies and a reconnaissance unit tasked with keeping an eye on coastal zones in the brigade's area of responsibility, as well as a unit to defend against chemical weapons attacks.

This is part of the plan to create a posture for effective response to new threats and diverse contingencies, including attack by guerrillas or special operation forces, NBC attack, invasion of remote islands and large-scale/ unconventional disasters, based on the geographic characteristics of the Nansei Islands, which consists of a large number of remote islands spread over a wide area. In organizing the 15th Brigade, an infantry regiment that is expected to play a central role in response to new threats and diverse contingencies will be newly established, while a chemical unit will be newly organized to improve NBC response capabilities. At the same time, necessary functions will be enhanced, such as air fleet posture, and the quality of defense capability will be improved, while enhancing mobility by introducing light armored vehicles and high-mobility multipurpose wheeled vehicles. The number of personnel will also increase from about 1,800 to about 2,100.

By expanding and strengthening these types of capabilities, the brigade can swiftly deploy its personnel to the disaster area to confirm the situation and conduct rescue operations and providing support to victims. The 15th Brigade will have higher capabilities for responding to new threats and diverse contingencies than the current 1st combined brigade. It will strengthen defense posture in the Nansei Islands.

The Chinese law on the protection of Chinese islands claims Chinese sovereignty over the Senkaku and other islands in the area. China could forcibly land on an uninhabited island, citing the protection of the island as a pretext for such action.

The Japanese government has requested the United States to allow Japanese Self-Defense Forces to jointly use a new U.S. base which the two governments are planning to build as an alternative to the U.S. Marine Corps Futenma Air Station in Okinawa. This was revealed by Defense Minister Kitazawa Toshimi at a press conference on 31 August 2010, where he released a bilateral report on construction options for the new base in Nago City’s Henoko district. The Ground SDF 15th Brigade had already carried out joint exercises with the U.S. Marine Corps at Camp Hansen in Okinawa. Kitazawa said at the press conference, “In addition to the issue of security, joint use of the new base by the SDF and the U.S. forces will help establish strong ties between the locality, the SDF, and the U.S, forces.”

Okinawans are hostile to the strengthening of the SDF due to the horrendous ground battle in Okinawa at the end of WW II in which the Japanese Imperial Army forced many residents to commit mass suicide. The SDF has been facing strong local opposition against its deployment in Okinawa’s Miyako and Yaeyama Islands.

Some 7,000 Marines of the headquarters of the 3rd Marine Expeditionary Force will relocate from Okinawa, Japan, to Guam over six years as part of recommendations accepted by the United States and Japan. The recommendations come out of the "2 plus 2" meeting hosted by Defense Secretary Donald H. Rumsfeld and including the Japanese defense minister, Yoshinori Ohno; U.S. Secretary of State Condoleezza Rice; and Japanese foreign minister Nobutaka Machimura.

According to the annual white paper released in July 2013, "....as well as acquiring 11 armored personnel carrier, 44 light armored vehicles, and one multi-purpose helicopter, in order to enhance defense readiness on land, including on islands such as the Southwestern Islands, amphibious vehicles shall be purchased as a sample and deliberations shall commence aimed at strengthening operational capabilities in relation to landings from the sea..."

In December 2015 it was reported that Japan would deploy 500 ground troops of its Self-Defense Forces (SDF) equipped with advanced surface-to-air and anti-ship missiles on islands in the western extremities of Okinawa Prefecture, a short distance (170 kilometers) from the uninhabited Senkaku/Diaoyu Islands, which China also claimed. The country's deputy defense minister, Kenji Wakamiya, met on 26 November 2015 with the mayor of Ishigaki - the closest inhabited island near the disputed archipelago - to explain the deployment plans.

The government was considering deploying a security unit for initial response if a remote island is invaded and a unit to operate surface-to-air and surface-to-ship missiles. The deployment would be completed during the next five-year medium-term defense buildup period, from fiscal 2019.