South Korea has been deeply scarred by its 2016 decision to deploy the U.S.-made Terminal High Altitude Aerial Defense (THAAD) missile defense system. Outraged that Seoul would downplay Chinese concerns and ignore warnings that deployment could "destroy" the two countries' ties, Beijing responded with economic punishment that reinforced the deeply felt sense of vulnerability among South Koreans and the belief that it is a small country — "a shrimp among whales" — that is more object than subject of regional relations.

Four years later, South Koreans remain wary of — and reluctant to take — any decision that risks offending China, even if it is intended to promote and protect their own national security.

That outcome no doubt delights policymakers in Beijing but it is the wrong lesson for South Koreans to have learned. Sadly, the response of Seoul's ally and partners has proven equally shortsighted: they prefer to criticize South Korean weakness when they should be figuring out ways to work with Seoul to blunt the impact of China's anger.