US framing of 2027 and tactical nuclear weapons deployment to Korea

By Choo Jae-woo

The talk of the town in defense circles in Seoul and Washington centers around two security issues. One is the U.S.' extended nuclear deterrence to South Korea and the other is the defense of Taiwan against China's possible attacks. Seemingly enough, they are two different stories. From the perspective of the respective subjects of concern, they are irrelevant to each other.

To the United States, both agendas are naturally complementary to the Indo-Pacific strategy. It became a revelation on Jan. 18 when the renowned Center for Strategic and International Studies (CSIS) released a report that recommended the U.S. "reconsider exercises that lay pre-decisional groundwork for the possible redeployment of U.S. low-yield nuclear weapons."

The CSIS report was well received by the Korean public as their fear of the North's nuclear threats builds to an unprecedented level. North Korea test-fired its nuclear-capable missiles on more than 70 occasions last year. It allegedly continues to advance its nuclear capacity both in quality and quantity.

As a result, a poll on Jan. 29 revealed that 76.6 percent of Korean respondents favored the development of nuclear arms. The last time when the Chicago Council on Global Affairs (CCGA) in 2020 surveyed Koreans, with regards to the re-deployment of tactical nuclear weapons, 68 percent wanted it. South Korean President Yoon Suk-yeol on Jan. 11 also displayed a position similar to that of the Korean public. His premise for either case was based on North Korea's nuclear threat prevailing.

While Koreans are obsessed with their vulnerability against the North's nuclear weapons, they have reservations about acting on behalf of the U.S. in defense of Taiwan. The Yoon government has also shown restraints on the topic. It is however feeling the pressure as Washington is redesigning its Taiwan defense posture at a rapid pace.

Starting in 2021, Washington has sought to lay a new pre-decisional groundwork for fortifying Taiwan's defense capability and military capacity. The White House and the U.S. Congress worked hard to build records for these shared goals. In the last two years, Congress introduced numerous bills that called for America's defense support to Taiwan.

A narrative for justifying their endeavor was sought and a politically correct consensus was finally reached with Chinese President Xi Jinping in his third term, last October. With consensus mounting that Xi will return for a fourth term in 2027, CIA officials and the Joint Chief of Staff have already framed the year 2027 as the year of a Chinese attack ― most likely on Taiwan.

The premise is that it will be almost impossible for Xi to prolong his tenure with anything but the unification of Taiwan. Especially given the longer-than-expected bleak prospects of the Chinese and global economies amidst U.S.-China competition.

At the core of the U.S.' evolving defense posture is the security of the Taiwan Strait. Without securing this area, the strategy is simply meaningless. The Taiwan Strait is the gateway to both geo-political and geo-economic defense networks initiated by the U.S. in the Indo-Pacific region.

Taiwan is an integral part of building a resilient global supply chain, particularly for semiconductors. The fate of freedom of navigation in the South China Sea and the Indian Ocean will be determined by the U.S. forces' accessibility to the strait. Largely because the majority of the forces are available from the Western Pacific.

The U.S. defense's schemes to fortify Taiwan against China were well reflected in the National Defense Appropriation Act (NADD), passed by Congress last December. Of the total 4408 pages, the act allocated 3108 pages to Taiwan's defense. The act stipulated the completion of U.S. fortification efforts by 2027.

But one critical element was missing: the nuclear weapons. Deployment of tactical nuclear weapons or nuclear armament might have been deemed too provocative for China. An alternative would be to make these weapons readily available in the vicinity of Taiwan. The U.S. has three options for deployment: Korea, Japan, and Guam.

Japan is out of the question since Okinawa is no longer under U.S. jurisdiction. For this reason, the United States had to withdraw all its tactical nuclear weapons from its bases in Okinawa in 1971. Japan still upholds its three non-nuclear weapon principles; Japan shall neither possess nor manufacture nuclear weapons, nor shall it permit their introduction into the country.

Guam is the farthest from Taiwan, approximately 1500 nautical miles (nm) as the crow flies, whereas Korea is only 800nm away and Okinawa 1400nm. Korea is therefore the most sensible option to extend America's nuclear deterrence for Taiwan.

Before the U.S. contemplates this option, Korea must seriously consider some of the following factors. First, how many tactical weapons would it take for an effective second strike capability against China and North Korea? Against a non-nuclear North Korea and China, the United States once deployed 600 nuclear weapons to the South in 1963. According to the U.S. Department of Defense report on China's military power released last November, the number of Chinese nuclear warheads deployed is estimated at 400. It predicted it would increase to 1000 by 2030 and 1500 by 2035.

Second, who will pay for their maintenance? Nuclear maintenance is far more expensive than warhead production.

Third, the U.S. nuclear deterrence for Taiwan from Korea would make Korea's involvement in the Taiwan Strait contingency a given one.

Last, is Korea prepared to live with all consequences of a nuclear arms race against North Korea and China?

Choo Jae-woo (jwc@khu.ac.kr) is a professor of international relations at Kyung Hee University and director of the China Center at the Korea Research Institute for National Security. He was a visiting fellow at the Brookings Institution.