South Korea’s decision to deploy the Terminal High Altitude Area Defense (THAAD) system has been a thorn in Beijing’s side for over a year. Sensitivities over the THAAD system’s radar capabilities led China to impose harsh sanctions on South Korea’s tourism sector and on key conglomerates, including (especially) the Lotte Group. Consequently, the recent resolution of this bilateral row has come as something of a surprise.
While the timing was unexpected, Beijing stands to benefit from a compromise on this issue at least three major ways. First, the agreement provides assurances from Seoul about China’s strategic position in the region. Second, the rapprochement between China and South Korea creates a better political environment for Beijing to deal with the current North Korea crisis. Finally, the agreement allows China to frame itself as the responsible power in the region while Trump is on his Asian tour.
Although Beijing failed to prevent South Korea’s deployment of THAAD altogether via unilateral sanctions and political pressure, the new agreement got Seoul to publically state it would abide by three "no’s": 1) no additional THAAD deployments in South Korea; 2) no participation in a US-led strategic missile defense system; and 3) no creation of a ROK-US-Japan trilateral military alliance. In essence, South Korea agreed to at least symbolically distance itself from a US-led strategy of containing China. Seoul left itself some wiggle room on these "no’s," but this agreement may be somewhat dissatisfying in Washington. US National Security Adviser H. R. McMaster welcomed the Sino-ROK detente, but he also hinted at US concern over South Korea’s possible decoupling from American-led security structures, saying that he does regard the three no’s as "definitive" in terms of official policy.