USFK Shifts Focus to China Deterrence in Unprecedented West Sea Drills

U.S. Forces Korea (USFK) scrambled dozens of F-16 fighter jets from Osan Air Base in Pyeongtaek, Gyeonggi Province, into the West Sea from the night of Feb. 18 through the early morning of Feb. 19, according to military sources.

The aircraft penetrated to the midpoint between South Korean and Chinese air defense identification zones before conducting patrol activities and returning to base.

The operation involved more than 100 sorties, making it an unprecedented large-scale exercise by assessment. USFK fighters approached close to China's Air Defense Identification Zone (CADIZ). China scrambled its own fighters in response, though no direct confrontation occurred between the two sides, sources said.

The independent exercise near CADIZ comes shortly after the United States released its new National Defense Strategy emphasizing enhanced strategic flexibility for USFK. The situation effectively created a U.S.-China military standoff near the Korean Peninsula.

USFK notified South Korean military authorities of the fighter jet sorties but did not disclose specific details including the nature of the training. However, South Korean military authorities are taking the matter seriously as U.S.-China military friction, previously confined to the East and South China Seas, has now occurred near the Korean Peninsula.

South Korea lodged a protest with the United States, sources said. Defense Minister Ahn Kyu-baek and Joint Chiefs of Staff Chairman Jin Young-seung reportedly called USFK Commander Gen. Xavier Brunson to convey their objections. USFK halted the exercise on Feb. 20 after receiving Seoul's protest.

The drills occurred after South Korea declined a U.S. proposal for trilateral air exercises among South Korea, the United States, and Japan. The U.S. and Japan proceeded with bilateral exercises in the East Sea and East China Sea on Feb. 16 and 18, deploying four B-52 strategic bombers.

Notably, the aircraft trained in the East China Sea stretching from south of Jeju Island toward Taiwan, then moved north and briefly entered West Sea airspace. The B-52 bombers appear to have participated in USFK's independent West Sea exercise on the same day.

The deployment of dozens of USFK fighters appears to have been intended to escort the B-52s entering the West Sea. The simultaneous operation of U.S. mainland strategic assets, Japan Air Self-Defense Force aircraft, and USFK fighters within the First Island Chain near the Korean Peninsula is unprecedented.

The B-52, alongside the B-1B and B-2, is one of three strategic bombers operated by the U.S. military. It can carry up to 30 tons of munitions, including nuclear-capable air-to-ground missiles such as the AGM-129, and can conduct precision strikes on targets more than 6,400 kilometers away.

Analysts interpret the B-52's unusual participation in both exercises as a China-focused move, signaling the U.S. has begun implementing the "qualitative posture adjustment" for forces stationed in the Indo-Pacific region that Washington has long promised.

The Trump administration's National Defense Strategy released on Jan. 23 formally announced "updating U.S. force posture" for USFK. Less than a month later, the U.S. appears to have begun translating policy into action.

Some analysts suggest this may signal USFK's role is shifting from "North Korea deterrence" to "China containment." USFK Commander Brunson has emphasized strategic flexibility, stating that USFK cannot be confined to the Korean Peninsula.

If this West Sea sortie represents part of enhanced China containment measures, similar exercises may recur. South Korean military authorities' decision to convey concerns to the U.S. side reflects this awareness.

Should West Sea tensions escalate like those in the East and South China Seas, South Korea risks being drawn into accidental conflicts, and domestic bases launching U.S. fighters could become potential targets. A U.S.-China military clash in the West Sea remains a serious concern.

Some observers note that America's strategic flexibility could translate into strategic uncertainty for South Korea. While the U.S. National Defense Authorization Act (NDAA) makes immediate USFK reductions or major role changes unlikely, concerns are emerging about the need to prepare for such scenarios.

USFK's unusual moves have created consternation within South Korea's military. USFK provided only last-minute notification and did not disclose the scale or purpose of the exercise, leaving South Korean forces to view it as effectively unannounced.

This context appears to have prompted South Korean military leadership to convey concerns to USFK. What is clear is that after 73 years of the ROK-U.S. alliance focused on defense against North Korea, USFK's role is beginning to shift toward China containment, making adjustments inevitable.