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In a joint statement by the US-Japan Security Council (2+2) on January 7, 2022, Japan told the US that funding for construction on Mageshima Island had been included in the 2022 fiscal year budget, settling a long-debated issue. The US agreed and welcomed this resolution.[1] This time, Japan took the initiative to allow Mageshima Island to be directly budgeted for renovation. It was originally only one of the alternatives for the replacement Field-Carrier Landing Practice (FCLP) base for the US carrier-based aircraft stationed in Japan. This was not only a big surprise to the residents of the Nishinoomote City, even the governor of Kagoshima Prefecture, Kōichi Shioda, protested directly to the central government, saying that the entire decision-making process was too hasty and did not respect the opinion of the local government.

Japan likely moved to quickly compromise on the issue because of continuing pressure from the US and a rapidly changing international situation. For Japan, the construction on Mageshima will not only help improve the training environment for the US military in Japan but also strengthen the US-Japan security system; giving it great significance. The project is expected to cost 318.3 billion yen (US$2.797 billion) and take about four years to complete (see Figure 2).[2]

There are three advantages of Mageshima: first, it is located in the northeast of the Nansei Shotō (Ryūkyū Islands); second, it is essentially an uninhabited island, so the impact from the base on the surrounding area, such as the noise or safety concerns of aircraft landing and taking off, are relatively small; third, the terrain is flat and large, so construction should be easier. Since one of the main strategic objectives of the Japanese Ministry of Defense is to strengthen the defense of the Nansei Shotō and to establish an appropriate and fast supply system in the region, Mageshima is suitable for playing this important role. Nansei Shotō is spread over a distance of 1,200 kilometers from north to south, about the same length as Honshu (largest of the four main islands of Japan). The Japanese SDF has only a limited number of bases in the area. With Mageshima prepared, the SDF and the US Forces in Japan will be able to take advantage of it to increase the depth of defense and keep China’s activities in the area in check.

Under the administrative jurisdiction of Nishinoomote City, Kagoshima Prefecture, Mageshima is located 12 km west of Tanegashima Island, with a flat area of 8.17 km2, 3.03 km east to west, and 4.5 km north to south. The highest point on the island, Takenokoshi, is in the center of the island at a height of about 71.7 meters. There is no regular ferry or resident on the island, but there are abundant fishery resources in the surrounding ocean.[3] The Japanese government bought the island in 2019 at a cost of 16 billion yen (about US$120 million) mainly to make the island an “unsinkable aircraft carrier”.[4] The Japanese government is rebuilding Mageshima to add a new training ground for the SDF and US Forces in Japan in both peacetime and in emergencies. The decision has two implications:

1. For SDF to conduct variety of exercises

According to Japan’s Ministry of Defense, a prepared Mageshima allows the SDF to conduct the following training on the island: first, fighter aircraft maneuvers such as F-35, F-15, F-2 emergency takeoff; second, normal terrain landing and takeoff training for C-130 transporters; third, water landing training for the Maritime Self-Defense Force US-2 amphibious planes; fourth, paratroop training for the Ground Self-Defense Force; fifth, helicopter tactical operations with airborne JGSDF troops; sixth, airdrop training for C-2, C-130, P-1, and P-3C. In addition, many new facilities will be added to the island, such as seaports, airports, hangars, fuel depots, ammunition depots, officer and soldier quarters, gymnasiums, supply depots, fire truck depots, control towers, officer quarters, and communication centers. This is all beneficial to strengthen Nansei Shotō defense by giving the SDF an additional base for supplies and support.[5]

2. Reducing flight distance and noise for US carrier-based aircraft in Japan

Since February 1982, the US carrier-based aircraft takeoff/landing training was mainly conducted from the Atsugi Base to the USS Midway outside Yokosuka Port. The training was carried out at night, making the noise quite disturbing for civilians. In 1993, the training was moved to Iwo Jima (1,200 km from the Atsugi base, see Figure 1), and the runways on Iwo Jima were modified to simulate the deck of an aircraft carrier for the pilots to conduct takeoff and landing training. In 2006, the US and Japanese governments agreed to move the US carrier-based aircraft from the Atsugi Base in Kanagawa Prefecture, which is a densely populated area, to the Iwakuni base in Yamaguchi Prefecture by March 2018.[6]

One of the most important reasons for the US-Japan 2+2 Security Council to build the Mageshima base is to allow the US carrier-based aircraft in Japan to conduct all-weather landing and takeoff training, and to reduce the training risks and restrictions from the long flight distance from the Iwakuni base to Iwo Jima (about 1,400 km, please see Figure 1). The flight distance from Iwakuni to Mageshima Island is about 400 km (see Figure 1), which also meets the requirements of the US. Moreover, since the island is uninhabited, the landing and takeoff noise during the training sessions will not affect the life of the civilians.

As soon as the US-Japan 2+2 Security Council decided to build an SDF base on Mageshima, residents of Nishinoomote City, including Kagoshima Prefectural Governor Kōichi Shioda, criticized the Japanese government for ignoring local opinions and the safety of residents. When Ministry of Defense officials went to Kagoshima Prefectural Office to explain the situation on January 13, about 30 residents protested outside the office to express their discontent.[7] Mr. Yaita, mayor of Nishinoomote City, said that from January 17, about 40 groups from both sides will be invited to attend closed-door meetings, and he will explain to the public after gathering information from all sides.[8] Proponents believe that since the government has already decided to build Mageshima, they will do their best to help the government with the construction. The only condition is that the government must first propose how the grant will be used to avoid local interests being compromised. As of now, the Japanese government has not specified the amount and duration of its annual subsidy to the local community; but on December 18, 2021, Japanese media revealed that the Ministry of Defense expects to subsidize the local community about 1 billion yen in the first year, but if the people do not accept the government’s decision, no subsidy will be given.[9] It’s rather like the government is bound to complete the plan. On the other hand, opponents stressed that the assessment of the overall environmental impact of the base construction is still in progress and has yet to have a clear result; it’s still too early to finalize the case.

The joint statement of the US-Japan 2+2 Security Council stated that the Mageshima base will be built. The implementation of the national policy requires the support and cooperation of the local government, so further communication between the central and local governments is necessary to achieve a win-win situation.

Fig. 1: The landing and takeoff training site of the US carrier-based aircraft in Japan (Note: Training is currently conducted from Iwakuni Base to Iwo Jima)

Figure 2: Construction plan for the Mageshima base