While it is certain that several countries will defy China’s ADIZ in the South China Sea one way or another, it remains unclear whether the South China Sea ADIZ represents a “red line,” the passage of which will trigger formidable countermeasures. Nevertheless, foreign reactions to a Chinese ADIZ in the South China Sea will likely be harsher than what happened with Beijing’s East China Sea ADIZ, which can be likened with the yellow card in soccer. The South China Sea ADIZ appears to belong to a weaker sense of red line that can be called “orange line.” In this sense, an orange line represents a watershed between what is tolerable and what is not, but the response to what is intolerable may or may not be very fearsome.

Alexander L. Vuving is a Professor at the Daniel K. Inouye Asia-Pacific Center for Security Studies. This article is adapted from the author’s “Guide to the South China Sea ADIZ,” written for the South China Sea Chronicle Initiative. The author wishes to thank Cai Ngoc Thien Huong for her research assistance and Van Pham for her initiative of a larger project on China’s ADIZ. The views expressed in this article and any possible mistakes are the author’s own.

Image: The HMS Daring en route to the Philippines. LA(PHOT) Keith Morgan/MOD.