Japan's Defence Ministry reported that Chinese military aircraft illuminated Air Self-Defence Force (SDF) fighter jets using fire control radar southeast of the main Okinawan island on December 6, amid intensifying diplomatic strain, Kyodo News reports. Prime Minister Takaichi Sanae expressed strong dismay on December 7, calling the action "extremely regrettable" and confirming that a stern protest had been lodged with the Chinese side, demanding steps to prevent any future occurrences. She affirmed that Japan would maintain a calm yet resolute approach and increase its air and sea surveillance efforts.

This incident, which saw Chinese military jets employ weapon targeting radar on Japanese aircraft, marks a significant escalation in the already fragile relationship between Tokyo and Beijing, underscoring the dangers of miscalculation in highly sensitive air and maritime spaces.

The Chinese J-15 aircraft, operating from the carrier Liaoning, intermittently illuminated the F-15s twice that afternoon—once near 4:32 pm and again close to 6:37 pm. The SDF planes maintained distance, preventing visual confirmation of the Chinese jets. Defence Minister Shinjiro Koizumi described the actions as "dangerous," going beyond the requirements for safe flight.

Vice Foreign Minister Takehiro Funakoshi also summoned the Chinese Ambassador to Japan, Wu Jianghao, to the Foreign Ministry in Tokyo to formally challenge the "perilous" behaviour. This marks the first public disclosure of such an incident by Japan’s Defence Ministry, which confirmed no harm came to the SDF aircraft or crew.

In contrast, China’s navy claimed on Sunday that Japanese SDF planes had repeatedly encroached upon and disrupted its naval training areas and airspace, though it did not acknowledge the use of targeting radar. Beijing's Defence Ministry conveyed its "strong dissatisfaction and firm opposition to Japan's provocations."

Experts believe the action was likely a political act of harassment rather than a prelude to a military strike, given the distance between the planes. However, this maritime friction follows Takaichi’s November 7 parliamentary statements suggesting a military attack on Taiwan could be a "survival-threatening situation" for Japan, drawing sharp criticism from Beijing, which views Taiwan as an internal matter. The radar lock-on incident follows a similar instance in 2013 involving a Chinese vessel targeting a Japanese Maritime SDF ship.