China is ramping up its military actions and raising tensions in the Nansei Islands. Japan is bolstering its presence in response. Locals are caught in the middle.
Faced with China’s rapid military rise, security tensions are growing in Japan, especially in the Nansei Islands, the southwestern chain that includes Okinawa.
The seriousness of the situation can be understood from the joint statement issued after the Japan-U.S. summit held on February 7 between Japanese Prime Minister Ishiba Shigeru and U.S. President Donald Trump. For the first time the statement cited the “increasing bilateral presence in Japan’s Southwest Islands” as one of the efforts to strengthen the alliance.
In the middle of February, as part of a press tour organized by the Foreign Press Center Japan, I visited three key military locations in the Nansei Islands: the Japan Air Self-Defense Force (JASDF)’s Naha Air Base, the Japan Maritime Self-Defense Force (JMSDF)’s Naha Air Base, and Yonaguni Island, the nation’s westernmost “border island.”
The “Air Fortress” in the Nansei Islands Region
The JASDF’s Naha Air Base is Japan’s “air fortress” in the Nansei Islands region, which spans about 1,200 kilometers from the Osumi archipelago off Kagoshima Prefecture – at the southern tip of Kyushu, the most southwestern of Japan’s four main islands – to Yonaguni near the Taiwanese coast. This length is comparable to that of Honshu, the largest of Japan’s four main islands.
In 2017, the Japanese Ministry of Defense upgraded the Southwestern Composite Air Division at the Naha Air Base to the Southwest Air Defense Force (SWADF) to strengthen the air defense system in the south of Japan.
Including the SWADF, the JASDF has four Air Defense Forces: the Northern Air Defense Force (headquartered at Misawa Air Base), the Central Air Defense Force (headquartered at Iruma Air Base), and the Western Air Defense Force (headquartered at Kasuga Air Base).
What is surprising is the size of the airspace that the SWADF is responsible for. It covers a vast expanse of skies that stretches about 920 kilometers east-to-west and 780 kilometers north-to-south.
A map showing the coverage area of the Southwest Air Defense Force. Map from the JASDF.
As China’s military activities around the Nansei Islands have become more intense, the mission of the Naha Air Base of the JASDF has become more challenging.
In response to foreign military aircraft approaching the country’s airspace, the SWADF scrambled aircraft some 401 times in fiscal year 2023, accounting for 60 percent of the total number of scrambles by the four Air Defense Forces nationwide. Since fiscal year 2013, when China established an Air Defense Identification Zone over the disputed Senkaku/Diaoyu Islands in the East China Sea, the number of scrambles has exceeded 400 every year.
However, SWADF points out that the Chinese military posture cannot be measured by the number of scrambles alone. This is because the quality of their activities has changed in recent years, with the operational area of Chinese military aircraft expanding and the People’s Liberation Army Navy (PLAN)’s aircraft carrier strike group passing through the straits of the Nansei Islands and operating regularly in the Pacific Ocean.
Specifically, Chinese military aircraft, which had operated over the East China Sea before 2012, have flown over the Miyako Strait and advanced into the Pacific Ocean since 2013. In addition, since 2015, they have also been operating over the Tsushima Strait and in the Sea of Japan (also known as the East Sea). Notably, China’s H-6 bombers and Y-9 intelligence gathering aircraft, as well as drones such as TB-001 and WZ-7, are becoming more prominent near Japan.
In addition, the PLAN’s Liaoning and Shandong aircraft carrier strike groups began to pass through the first island chain between Kyushu and the Philippines in 2022, and now conduct regular training in the Western Pacific.
Moreover, both the geographic area and the frequency of joint training between China and Russia are increasing. Joint patrols by Chinese and Russian military aircraft, which began in July 2019, initially only occurred over the Sea of Japan and the East China Sea. However, in December 2020, they passed over the Miyako Strait for the first time and entered the Pacific Ocean. The frequency of patrols has also increased, from once a year to twice a year in May and December 2022 for the first time. Their joint trainings were held for two consecutive days each in June and December 2023 for the first time.
A spokesperson at the SWADF said he “cannot answer [questions about] China’s intentions,” and the JASDF plans to continue to monitor the situation and improve its response capabilities.
The JMSDF Naha Air Base
To ensure safety in the waters around the Nansei Islands and the East China Sea, the JMSDF’s Naha Air Base’s Fleet Air Wing 5 conducts surveillance and intelligence gathering 365 days a year.
It is part of the Fleet Air Force, the unit in the JMSDF that operates aircraft, and mainly utilizes P-3C patrol aircraft.
Rear Admiral Hiraki Takuhiro, commander of the Fleet Air Wing 5, stressed the importance of the Fleet Air Wing 5’s mission. “There are about 2,000 islands in the East China Sea. And there are many sea routes, including straits, that go from the East China Sea to the Pacific Ocean,” he told media. “This is different from other areas, and we recognize that it is very important.”
However, the JMSDF is not responding to China Coast Guard vessels approaching the Senkaku Islands. In response to a question on the subject, Hiraki said, “My understanding is that the Japan Coast Guard is responding to the activities of the China Coast Guard. We are not taking any action.”
A journalist asked a follow-up question: “The Japan Coast Guard has the main role in missions around the Senkaku Islands, but under what circumstances would the JMSDF be deployed?” Hiraki replied, “It’s a legal matter, but if there is a request that goes beyond the scope of police power, the JMSDF will be deployed.”
During this press tour, journalists heard about the historical background of the Senkaku Islands from Takara Kurayoshi, professor emeritus of the University of the Ryukyus and former vice governor of Okinawa Prefecture.
