China’s unilateral drawing of its new air defense identification zone that partly overlaps with South Korea’s appears to have made Seoul officials recognize again the complexity of the work needed to strike a delicate strategic balance among major regional powers.

Saturday’s announcement of the Chinese ADIZ, which includes airspace over a South Korean-controlled submerged rock called Ieodo and a set of islands claimed by both China and Japan, has prompted protests from Seoul and Tokyo. The U.S. also came forward to denounce the move as escalating tensions in Northeast Asia.

This situation contrasts with the united front that has been staged by South Korea and China over historical issues with Japan. To avoid provoking China, South Korea has also refrained from concluding a military cooperation accord with Japan and joining a U.S.-led global missile defense program. Washington has helplessly seen Seoul and Tokyo, its two key allies in the region, locked in deepening discord over historical and territorial matters, while keeping a cautious watch over South Korea’s efforts to upgrade its partnership with an increasingly assertive China.

The Seoul government called in Chinese Embassy officials Monday to express regret over Beijing’s move, conveying its stance that it would not accept the unilaterally drawn line. It should have made a more prompt and resolute response.

South Korea needs a rethink on ways it has handled territorial issues with neighboring powers. The country should clarify its stance more actively and articulately.

It is seen as too lukewarm for Seoul to have left the sky over Ieodo beyond South Korea’s air defense zone, while Japan’s ADIZ, announced in 1969, includes it. South Korea needs to consider placing Ieodo in its zone as the country closest to the submerged rock.

China has expressed hope to contain fallout from the controversy with South Korea, emphasizing the need for resolution through “friendly consultations and negotiations.” A bilateral defense meeting set to be held in Seoul on Thursday will be a stage to test the sincerity of Beijing’s attitude. Regardless of the outcome, Seoul officials should be armed with more sophisticated and far-sighted strategies to secure the best possible interests in the increasingly tense regional situation.