The recent crisis on the Korean Peninsula has once again brought to the fore China’s support for North Korea, which many deem vital for Pyongyang’s survival. In explaining this support analysts typically cite two factors: Beijing’s fear that the North Korean regime’s collapse will bring untold numbers of refugees across the border into China, and Beijing’s fear of a unified, democratic, and pro-American Korea under Seoul’s leadership with a large U.S. troop presence stationed on the Sino-Korean border.
These factors probably accurately reflect Beijing’s strategic calculus. However, although possible, it’s not at all clear that a unified Korea under Seoul’s tutelage would in fact be as pro-American as Western and (presumably) Chinese policymakers assume. A number of factors could undermine this assumption.
The first one being the process that unification takes. Even assuming the North Korean regime collapses and is quickly unified under Seoul’s leadership, there are a number of different ways this can unfold. One of the most plausible is that Chinese troops would rush across the Yalu River at the same time that ROK troops came across the DMZ in the south. In the process China would come to occupy a sizeable chunk of North Korea, which would also likely contain some of Pyongyang’s nuclear and other WMD programs. Beijing would therefore have powerful leverage in bargaining the terms of its withdrawal from Korea. This would almost certainly be used to extract concessions from Seoul and Washington on the U.S. presence north of the DMZ.