By Chen Wei-chen | 2025-12-18

Amid a diplomatic row between China and Japan now in its second month, Beijing has escalated its military presence in Northeast Asia. Japanese Defense Minister Shinjiro Koizumi, on X, criticized China for its "expansion and intensification" of Chinese maneuvers and intent "to demonstrate force against our nation."

On December 10, two US Air Force B-52H bombers joined Japan Air Self-Defense Force F-15J and F-35A fighters over the Sea of Japan for a series of tactical exercises. The drills reaffirm the allies' resolve "not to tolerate unilateral changes to the status quo by force" and to strengthen "the deterrence and response capabilities of the Japan-US Alliance," Japan's Joint Staff Office tweeted.

The exercise took place "amid an increasingly severe security environment surrounding our country," Japan's Ministry of Defense said separately.

Tensions with Beijing have spiraled upward in recent weeks.

Sino-Russian joint patrol

The US-Japanese operation followed a Sino-Russian joint patrol a day earlier. On December 9, Russian and Chinese bombers conducted coordinated flights over the East China Sea and the western Pacific, prompting Japanese and South Korean fighter jets to monitor the activity.

According to Japanese officials, two Russian Tu-95 bombers linked up with two Chinese H-6 bombers before flying toward the Pacific Ocean off the coast of Shikoku. Chinese J-16 fighters joined the formation as it transited the Okinawa-Miyako corridor into the Philippine Sea.

A second group of four J-16's accompanied the bombers on their return leg, again transiting the Okinawa-Miyako corridor back toward the East China Sea.

In his denunciation of the Sino-Russian aerial operation, Japan's Koizumi called it a "serious concern for national security."

He later discussed the situation with US Secretary of War Pete Hegseth by phone. The two ministers agreed that Beijing's actions were "not conducive to regional peace and stability," vowing that their respective forces "would firmly and steadily continue surveillance and monitoring activities" surrounding Japan, according to a statement.

The latest standoff followed comments by Japanese Prime Minister Sanae Takaichi that infuriated Beijing. In early November, she raised the possibility of Japanese involvement in the event of a Chinese attack on Taiwan.

Dangerous aerial encounters

The patrols came after days after a close military encounter at sea. On December 6, Chinese fighters from the aircraft carrier Liaoning twice locked their fire-control radar on Japanese aircraft over international waters southeast of Okinawa, an act Tokyo described as highly hostile.

Tokyo lodged a strong protest, but Beijing denied the accusation, countering that Japanese aircraft had "maliciously followed and harassed" its carrier.

Reuters described the radar targeting as "the most serious run-in between the two militaries in years." The last such radar lock-on incident occurred in 2013 near the disputed Senkaku Islands, which Japan administers. China and Taiwan both have rival claims to the islands and call them the Diaoyus.

Sino-Japanese relations have plunged to their lowest point in over a decade.

De-escalation will be far more difficult than it was during past Sino-Japanese crises, Bonny Lin and Kristi Govella, senior advisers at Washington's Center for Strategic and International Studies, wrote earlier in December.

They listed a number of Chinese and Japanese political factors for their theory, including China's view of Taiwan as "the core of Chinese core interests" and widespread Japanese concerns over Chinese behavior.

Even if tensions eventually ease, relations are likely to stabilize at a "new, worse normal," Lin and Govella said.

Takaichi has advanced the agenda of her mentor, Shinzo Abe, by beefing up defense and treating Taiwan's security as a primary interest, Sebastian Maslow, a political science professor at the University of Tokyo, wrote on The Conversation. While a more confident China maintains its pressure, Japan has become more resilient, having learned from past crises to reduce risk to its supply chains. "A quick end to the crisis is not in sight," wrote Maslow.