IRIA News

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An explosion at a munitions storage facility within the U.S. Kadena Air Base on Japan’s southern island of Okinawa injured four members of the Japan Ground Self-Defense Force (JGSDF) on June 9, 2025.

According to Japanese Defense Ministry officials and Okinawan authorities, the blast occurred while JGSDF personnel were handling unexploded wartime ordnance, remnants of World War II that continue to be unearthed across the island.

“The explosion occurred at the facility managed by the Okinawa prefectural government at Kadena Air Base’s munitions storage area,” the U.S. Air Force said in a statement. “No U.S. servicemembers were involved in the incident.”

Japanese media reported that the explosion took place while the soldiers were attempting to remove rust from one of the devices. The sudden detonation inflicted finger lacerations and possible hearing damage on the four soldiers, though none of the injuries are believed to be life-threatening.

“There was an unidentified explosion while SDF personnel were preparing for bomb disposal operations,” a Defense Ministry official stated. “Those in close proximity suffered finger lacerations and possible hearing damage.”

Authorities confirmed that no evacuation orders were issued for nearby residents, and there is no current risk of secondary explosions or fire. Okinawa Prefecture, which manages the temporary storage of unexploded ordnance found on the island, is working in coordination with Japan’s Self-Defense Forces to assess the cause of the accident. The SDF is currently investigating what triggered the blast.

Military presence in Okinawa

The incident underscores the ongoing hazards posed by unexploded ordnance in Okinawa, which was the site of one of the bloodiest battles in the Pacific theater during World War II. The 82-day Battle of Okinawa in 1945 left more than 200,000 people dead, roughly half of them civilians, and devastated the island’s infrastructure. Thousands of unexploded bombs and shells remain buried throughout Okinawa, frequently discovered during construction or agricultural activities.

Following Japan’s defeat in 1945, Okinawa came under U.S. administration until its formal reversion to Japanese sovereignty in 1972. Despite the reversion, Okinawa continues to host a disproportionate share of U.S. military installations under the U.S.-Japan Security Alliance.

US Forces in Okinawa

As of 2025, Japan hosts approximately 54,000 U.S. military personnel, the largest forward-deployed force of the United States in the Asia-Pacific region. More than 25,000 of these are stationed in Okinawa, accounting for nearly half of all American military personnel in Japan.

Kadena Air Base is the largest U.S. Air Force installation in the Far East and plays a critical role in regional deterrence, surveillance, and rapid response capabilities. It spans 6,500 acres and supports about 18,000 American servicemembers and their families. The base houses fighter squadrons, aerial refueling tankers, and reconnaissance aircraft.

Other significant U.S. military facilities in Okinawa include Marine Corps Air Station Futenma, Camp Schwab, and Camp Hansen. The island, despite occupying less than 1% of Japan’s total land area, bears the burden of hosting about 70% of the land area allocated to U.S. military bases in the country.

Strategic importance and public frustration

Okinawa’s geographic proximity to Taiwan, the Korean Peninsula, and the contested waters of the South China Sea makes it a strategic lynchpin for U.S. military operations in East Asia. American and Japanese officials argue that the bases are essential for maintaining peace and stability in the region amid rising tensions with China and North Korea.

However, this strategic value comes at a cost to local communities. Okinawans have long expressed frustration over noise pollution, environmental damage, and safety concerns related to the U.S. military presence. Incidents such as aircraft crashes, crimes committed by U.S. personnel, and accidents involving military equipment have further strained relations.

The recent explosion has added another layer of concern for local residents who have dealt with decades of military-related hazards.

According to Okinawa Prefecture’s data, over 1,600 tons of unexploded ordnance have been removed since the end of the war. In recent years, the Self-Defense Forces have disposed of more than 30,000 items annually, many found during routine construction work or agricultural activities.

Japanese Ground Self-Defense Force units are specially trained to handle such ordnance. Despite rigorous safety procedures, accidents like Monday’s incident show that the work remains dangerous even decades later.

While Monday’s explosion did not lead to fatalities or widespread damage, it has once again highlighted the complex interplay between Japan’s military history, its alliance with the United States, and the lived experiences of Okinawans today. With tensions in the Asia-Pacific region on the rise and the strategic value of U.S. bases only growing, incidents like these may become flashpoints in the broader debate over Okinawa’s future.