In his recent visit to South Korea, US Secretary of War Pete Hegseth affirmed that US troops based in the country could be used to deter regional threats, the most important being a Taiwan contingency. South Korea has balked at the US suggestion, but considering the US pivot to homeland defence, the pressure on South Korea to contribute to US regional deterrence will only increase.
The proposed expansion of US Forces Korea (USFK) mission to cover China will have major repercussions for China-North Korea relations. In the past, the frequently asked question was: were North Korea to invade South Korea, would China intervene? Now, the question needs to be reversed. Will North Korea come to China’s defence if Beijing’s invasion of Taiwan triggers a US military intervention? North Korea fulfilling its treaty obligation with Russia by helping Moscow fight against a Ukrainian invasion of Kursk means Pyongyang takes its commitment seriously, hence it is not a far-fetched question to ask the same of the China-North Korea alliance. The answer to this question depends on how China and North Korea understand and interpret Article II, or the mutual defence clause, in their 1961 Treaty of Friendship, Cooperation and Mutual Assistance.
Article II reads:
“In the event of one of the Contracting Parties being subjected to the armed attack by any state or several states jointly and thus being involved in a state of war, the other Contracting Party shall immediately render military and other assistance by all means at its disposal.”
What is missing from the clause is who started the shooting. The ambiguity leaves open the possibility of China coming to North Korea’s defence if a North Korean invasion of the South turns awry due to a US-South Korean retaliation.
Indeed, this is what happened in 1950 when China intervened to save North Korea after its invasion led to a US-South Korea march north. The ambiguity is because of the Sino-Soviet Split. China, out of its ambition to detach North Korea from the Soviet orbit, did not insert a strong escape clause to disincentivise a North Korean first strike.
The most cost-effective way for Pyongyang to meet its treaty obligation without being entrapped into a regional war is to launch low-level provocations against Seoul.
The collapse of the Soviet Union allowed China to scale back some of its security commitment to North Korea. In 2017, amid the US-North Korea nuclear brinkmanship, China curtailed this ambiguity by telling North Korea that Beijing would not rescue North Korea if it attacked the United States first. North Korea however has not made any public statements regarding the new interpretation of Article II. The treaty renewal in 2021 did not reflect this interpretation of the Chinese commitment.
A US intervention against a Chinese invasion of Taiwan technically subjects China to an armed attack under the treaty’s purview. There is little escape room for Pyongyang because it recognises Taiwan to be a part of China and the treaty scope covers the “Far East”. Even if China starts the shooting, North Korea is still obligated to defend it as the text of Article II has not changed. Russia started the invasion of Ukraine, but North Korea helped it anyways.
However, Pyongyang cannot significantly divert its military power away from the Korean peninsula, for a related reason to explain Seoul’s dubious response to the expansion of the USFK mission. North Korea’s navy is no match for that of the US-South Korea-Japan bloc and it lacks maritime power projection capability to be useful for a Chinese invasion of Taiwan. North Korea also doesn’t want to launch missile attacks against US regional bases in South Korea, Japan, the Philippines, or Guam for fear of retaliation. Pyongyang’s rejection of unification also means it will not exploit the USFK distraction to conquer Seoul by force as the South Korean military alone is still superior to the North Korean military. “By all means at its disposal” doesn’t necessarily mean North Korea will restart the Korean war.
The most cost-effective way for Pyongyang to meet its treaty obligation without being entrapped into a regional war is to launch low-level provocations against Seoul to pin down the USFK. These provocations may include propaganda broadcasts along the border, drone incursions, intrusion of South Korean water near the Northern Limit Line, leaflet droppings, or missile tests. Low-level provocations can overburden South Korean and USFK facilities and stretch the allied reconnaissance capability. The United States, distracted by Taiwan, will not invade or encourage Seoul to respond forcefully to Pyongyang’s low-level provocations.
China is likely to support North Korea’s low-level provocations because they can keep Washington distracted without provoking a full-scale conflict involving China in Korea. With China’s approval, North Korean troops can help pacify Taiwan and learn how the United States fights a war in the Pacific. These provocations matter not only militarily but they will also help North Korea drive a hard bargain with Washington, Seoul, and Beijing, just like it is doing with Moscow thanks to its military presence in Kursk.
It is important to stress that the level of North Korean provocations may be coordinated pre-invasion so that both China and North Korea can avoid any misunderstanding of obligation or miscalculation of escalation risk. China and North Korea will also see if the South Korean military is involved in a Taiwan contingency to determine the appropriate level of escalation. Russia’s invasion of Ukraine has become a boon for North Korea. It will similarly look to benefit from a China’s invasion of Taiwan.
