Pentagon strategy highlights South Korea’s deterrence role

In its new National Defense Strategy released on Jan. 23 local time, the Donald Trump administration said South Korea has the capacity to assume primary responsibility for deterring North Korea, with U.S. support described as “critical but limited.” The document also urges allies, including South Korea, to "bear their fair share of the burden for collective defense.” The language is widely seen as signaling a strategic shift in which Washington prioritizes countering China while expecting Seoul to take the lead in addressing the North Korean threat. Analysts say the strategy may also foreshadow future adjustments to the size, role or posture of U.S. Forces Korea as part of this broader realignment.

The National Defense Strategy, drafted by the U.S. Department of Defense, serves as a supporting document to the National Security Strategy, the White House’s highest-level framework for foreign and security policy. It serves as a core blueprint for U.S. military posture, planning and operations. Both the NSS and the NDS are typically issued only once during a president’s four-year term. The current NSS was released on Dec. 4 last year.

The latest NDS explicitly designates South Korea as having primary responsibility for deterring North Korea, stating, “South Korea is both willing and able to do so in the face of a direct and clear threat from North Korea.” The document points to Seoul’s strengths, including its strong conventional military capabilities, high level of defense spending, advanced defense industry and mandatory conscription system. The assessment is widely interpreted as a call for South Korea to further bolster its conventional forces, take greater initiative in responding to North Korean threats and assume a more active role in broader efforts to counter China. At the same time, the United States signaled its intention to concentrate on strengthening homeland defense and enhancing air and missile defense capabilities in the Indo-Pacific region to contain China’s rise.

The NDS assesses that North Korea poses a direct military threat to South Korea and Japan, noting that its missile forces are capable of striking targets in both countries with conventional weapons as well as nuclear or other weapons of mass destruction. It also characterizes North Korea’s nuclear arsenal as “a clear and present danger” to the U.S. homeland. As with the new National Security Strategy, however, the NDS makes no reference to the denuclearization of North Korea.

The strategy also reiterates President Donald Trump’s long-standing emphasis on strengthening U.S. influence across the Western Hemisphere, including the Americas, Europe and parts of West Africa. Through this approach, the document says Washington aims to bolster homeland defense while ensuring U.S. military and commercial access to Greenland, the Gulf of America and the Panama Canal.


Jin-Woo Shin niceshin@donga.com