At a news conference in Seoul today, the United States and the Republic of Korea jointly announced the decision to deploy a Terminal High Altitude Area Defense (THAAD) missile defense system on the Korean Peninsula, with operational deployment planned by the end of 2017. Though many details are still pending, the decision is not a surprise, and the purposes of the deployment are wholly transparent.

As elaborated in the official announcement, the THAAD deployments are intended to defend the infrastructure and citizens of South Korea, and to protect core military capabilities underpinning the U.S.-Korea alliance. It is not a panacea for South Korea’s potential vulnerabilities to North Korean missile attack, but it will appreciably buttress Seoul’s still-limited air and missile defense capabilities, and explicitly link them to the far greater assets of the United States. 

Seoul did not undertake this commitment lightly. In recent years, South Korean strategic analysts have hotly debated the missile defense issue, but the political-military leadership has proceeded very deliberately. It was only in the aftermath of North Korea’s fourth nuclear test in early January and a long-range rocket test that soon followed that President Park Geun-hye’s administration agreed to initiate consultations on the “earliest possible” deployment of a THAAD missile battery. The North’s accelerated missile testing program, evident since April, reinforced the need for a meaningful response to Pyongyang’s actions.

Neither China nor Russia seems mollified by today’s announcement. Beijing and Moscow both perceive a malign U.S. strategic design, purportedly intended to detect and intercept Chinese and Russian strategic missiles, thereby invalidating their respective deterrence capabilities. But these worst-case estimates attribute technical reach and refinement to the Raytheon radar system likely to accompany the THAAD deployment that substantially exceeds even the manufacturer’s claims. 

China and Russia also contend that the THAAD deployment will further complicate the larger goal of denuclearization and threat reduction on the Korean Peninsula. But this places the cart before the horse. Pyongyang’s determination to expand and diversify its nuclear and missile programs has triggered the THAAD decision. Without the North’s accelerated military efforts, it is very doubtful that sentiment in Seoul would favor deployment of THAAD. Beijing and Moscow assuredly know how to connect the dots, but they seem unwilling to do so. 

At a time of increased Chinese wariness about U.S. military strategy along China’s periphery, it is not a surprise that Beijing has paid little heed to American and South Korean assurances.

Beijing also calculates that warning South Korea of unspecified consequences will convince Seoul to forego the THAAD decision. But this underestimates the South’s determination to proceed with missile defense, which will tie Seoul even more integrally to longer-term cooperation with the United States. This decision is unwelcome in China, but it is wholly within Seoul’s sovereign right to defend its vital interests by all appropriate means; China routinely does the same.

In meetings with Chinese counterparts, senior Korean officials have repeatedly stated that the THAAD deployment serves one irreducible purpose: the protection of South Korean vital national security interests. Seoul is keenly aware of Chinese strategic equities, and will remain very mindful of Beijing’s concerns as it moves ahead with this program. 

At the same time, Seoul and Washington have repeatedly conveyed their willingness to impart to officials in Beijing the limited purpose of the THAAD deployment. It will be directed entirely towards the North’s threats against the South; it will be exclusively bilateral in design; and it will not be targeted against the capabilities of any other party. 

At a time of increased Chinese wariness about U.S. military strategy along China’s periphery, it is not a surprise that Beijing has paid little heed to American and South Korean assurances, at least publicly. But officials and analysts in China must quietly grasp the reasons for the THAAD decision. The North’s nuclear and missile programs worry China deeply, as well. 

The need for a quiet, private conversation about the risks to stability on the peninsula has never been greater. The United States and South Korea are surely ready for this conversation. Whether China is ready remains to be seen.