A fatal crash of a U.S. military Osprey airplane in Japan late last month has reignited safety concerns among local citizens, further fueled by Washington continuing to fly the tilt-rotor aircraft despite a request by Tokyo to ground them.
Pundits say the United States should respond to Japan's demand for better operations at its military bases in the Asian country, while Tokyo should insist that Washington halt Osprey flights and provide detailed information related to the latest incident.
They warn that if the poor handling of the accident by the two governments erodes public support for their alliance, it could weaken their deterrence in the remote islands of southwestern Japan amid China's growing military assertiveness in nearby waters.
The crashed aircraft, one of the six U.S. CV-22 transport aircraft assigned to Yokota Air Base in the western suburbs of Tokyo, disappeared from radar on Wednesday afternoon off the island of Yakushima in Kagoshima prefecture, southwestern Japan.
The U.S. Air Force said the Osprey, which was carrying out routine training, had eight airmen on board, with the cause of the accident still unknown.
On the same day, the Japan Coast Guard confirmed the death of one crew member, marking the first-ever fatality in Japan resulting from an accident involving Ospreys. The fate of the remaining crew members is still unknown.
"Clearly, a thorough investigation regarding the safety of the aircraft is necessary," said Mike Mochizuki, an associate professor of political science and international affairs at the George Washington University in the U.S. capital.
"If the United States does not comply with" Tokyo's request to ensure the safety of Osprey flights, it will undermine the "Japanese public's trust and support" for the bilateral alliance, the expert in relations between the two countries said.
Following the crash, Tokyo called on Washington to suspend Osprey flights, except for search and rescue operations, until safety is confirmed. The Japan Self-Defense Forces have decided to refrain from flying its V-22 Ospreys "for the time being."
The U.S. Forces Japan, meanwhile, has effectively ignored the demand by continuing to operate Ospreys other than CV-22s.
Japan's Chief Cabinet Secretary Hirokazu Matsuno, the top government spokesman, has expressed "concerns" that the United States has continued to fly Ospreys "without sufficient explanation about safety" despite repeated requests from Tokyo.
Takuma Nakashima, a professor of Japanese political and diplomatic history at Kyushu University, said, "In terms of national security, it is very detrimental" for Tokyo and Washington "to find themselves in a situation of mutual distrust."
He added Japan and the United States should avoid damaging the credibility of their alliance through routine communication, especially as they are ramping up their defense capabilities to counter China's military buildup in the Indo-Pacific region.
Ospreys, capable of taking off and landing like helicopters but cruising like planes, have a track record of accidents and mishaps in Japan and abroad.
In 2016, an MV-22, the variant used by the U.S. Marine Corps, crash-landed off Okinawa in southern Japan, injuring two crew members. Crashes in Australia in 2017 and August this year both resulted in three fatalities.
U.S. forces in Japan commenced deployment of six MV-22s at its Marine Corps Air Station Futenma in Okinawa in 2012. Currently, 24 MV-22s are stationed at the base in the prefecture that hosts the bulk of U.S. military facilities in the Asian nation.
On Thursday, Okinawa Gov. Denny Tamaki said it is "very regrettable" that U.S. Ospreys keep operating while the cause of the accident has yet to be identified. The mayor of the city, where the Futenma base is located, condemned the move for "amplifying fears among citizens."
Tokyo should continue demanding Washington explain the latest accident swiftly and accurately, given that the smooth operation of U.S. bases in Japan hinges on to what extent people living near them understand the necessity of their functions, Nakashima said.
The experts also pointed out that the crash could delay the Japan Ground Self-Defense Force's plan to relocate its V-22 Osprey aircraft from a temporary deployment site in Kisarazu, near Tokyo, to Saga in the southwestern area of the country by 2025.
The postponement would affect the strategies of Japan and the United States to tackle China's military rise, as the relocation is part of Tokyo's efforts to strengthen defense capabilities, together with its ally Washington, in the southwestern Nansei island chain.
The Nansei chain includes the Tokyo-controlled, Beijing-claimed uninhabited Senkaku Islands, around which Chinese coast guard vessels have repeatedly entered the waters near the islets, although Japan has continuously lodged protests over the issue.
Matsuno said Japan has no intention of changing the relocation plan even after the fatal incident, while emphasizing that the government will take local safety concerns "seriously."