The United States and Japan carried out bilateral air drills last week after South Korea rejected a proposed trilateral exercise. The U.S. military conducted joint training with Japan's Air Self-Defense Force involving four B-52 bombers in the East Sea and East China Sea on February 16 and 18.

The drills followed a U.S. proposal in mid-January for trilateral aerial exercises among the U.S., South Korea, and Japan sometime in February. South Korea turned down the plan because the suggested timing overlapped with its Lunar New Year holiday from February 15 to 18 and fell just before Japan's annual Takeshima Day commemoration on February 22. Takeshima Day, organized by Japan's Shimane Prefecture, asserts Tokyo's territorial claims over the Dokdo islets, which South Korea administers and considers part of its territory.

Seoul's Ministry of National Defense proposed rescheduling the trilateral drills earlier or conducting bilateral U.S.-South Korea training after February 22, but the U.S. rejected the counteroffer. Instead, U.S. Forces Korea performed a solo aerial exercise off South Korea's west coast on February 18, while proceeding with the separate sessions alongside Japan.

South Korean officials denied any rift with their allies. Defense Ministry spokeswoman Chung Binna, also referred to as Jeong Bit-na in some reports, stated that the U.S.-Japan exercises were unrelated to trilateral cooperation plans and expressed regret over media portrayals of conflict. She emphasized that coordination for security cooperation among the three nations continues smoothly and reaffirmed the strength of the U.S.-South Korea alliance.

The incident highlights ongoing sensitivities in South Korea-Japan relations stemming from the Dokdo-Takeshima dispute, located about 150 miles east of the Korean Peninsula. It echoes past instances where timing near Takeshima Day complicated joint activities, such as during the Moon Jae-in administration, when similar U.S. trilateral proposals led to bilateral pairings.

These aerial exercises served as precursors to larger annual training. The U.S. and South Korea plan to hold their Freedom Shield combined exercise from March 9 to 19 without reductions, focusing on field maneuvers and verifying Seoul's wartime operational control capabilities. Separately, the U.S. and Japan recently completed the Keen Edge tabletop drill from January 29 to February 5, simulating counterattacks with long-range missiles against enemy sites in an armed attack scenario on Japan's Nansei Islands.

The bilateral U.S.-Japan activities underscore efforts to bolster deterrence amid threats from North Korea, which has condemned past joint drills as provocative. Despite the scheduling hiccup, all parties maintain that trilateral security cooperation remains a priority for regional stability.