► Washington Declaration paved the way for what hitherto has been the US extended deterrence to morph into Korea-US extended deterrence.

► Through joint planning and training, and incorporation of Korea’s conventional weapons support for US nuclear operations, the Korea-US alliance would be able to strengthen deterrence capabilities to a level different from the past through the concretization of ‘Korean-style extended deterrence’ that Korea and the US would work together on.

► By implementing follow-up measures with the U.S., the Yoon administration must build on the new extended deterrence system that is concrete and substantial enough for the Korean people to realize the results of the Washington Declaration.

Introduction

Among the many accomplishments from President Yoon’s state visit to the U.S., the most notable achievement is by far the adoption of the ‘Washington Declaration’. As President Yoon mentioned, the ROK-U.S. Mutual Defense Treaty signed in 1953 is based on conventional forces. Considering North Korea’s evolving nuclear threat, an ‘upgraded version’ of the Mutual Defense Treaty that included not only conventional weapons but also nuclear weapons was inevitable. The Yoon administration has been discussing ways to increase South Korea's participation in the deployment of U.S. strategic assets, including nuclear weapons, by restarting the suspended ROK-U.S. Extended Deterrence Strategy and Consultation Group (EDSCG). What are the significances of Washington Declaration?

Stipulation of Extended Deterrence in the Text

The U.S. currently provides tailored extended deterrence to NATO allies in Europe and its Asian allies; however, extended deterrence is not stipulated in a statutory document. The Washington Declaration is significant in that it integrated the dialogues of the EDSCG, outlined them in a joint statement after the summit, and publicly announced them in a Declaration. Although it is not legally binding, it is on par with the Mutual Defense Treaty considering the significance of the joint statement of the two leaders. Washington Declaration paved the way for what hitherto has been the US extended deterrence to morph into Korea-US extended deterrence.  

Deployment of SSBNs

As one of the subsequent measures of the Washington Declaration, the U.S. has pledged to deploy nuclear-powered ballistic missile submarines (SSBNs) more regularly to the Korean Peninsula. Until now, the U.S. was reluctant to South Korea’s call for the deployment of SSBNs because of the high cost of deployment and the possibility of extensively provoking North Korea. As SSBNs can operate underwater for long periods, North Korea will not be able to detect a retaliatory nuclear strike by the U.S., which provides another level of deterrence in addition to ground-based U.S. nuclear weapons. SSBNs equipped with low-yield nuclear warheads can be effective in preemptively and precisely striking North Korea’s imminent nuclear attacks. Although the SSBNs are not stationed permanently, the deployment is a groundbreaking measure displaying the U.S. commitment to retaliate against North Korea's nuclear threats with stronger extended deterrence.

Instituting NCG

Perhaps the most notable achievement is the establishment of the Nuclear Consultative Group (NCG) between South Korea and the U.S., which is a practical measure to carry out the Washington Declaration. Under extended deterrence, the U.S. is committed to drawing on the full range of its military capabilities, including nuclear, conventional, and missile defense (MD) capabilities. Among these military capabilities, the NCG is a bilateral consultative group dedicated to discussions on nuclear deterrence (nuclear umbrella), which is quite unprecedented. The U.S. already has a consultative body with its NATO allies, the Nuclear Planning Group (NPG) established in 1966 for ‘nuclear sharing’. If the ROK-U.S. NCG operates effectively and consistently as President Yoon asserted, it may be more operative than NATO’s NPG because unlike the NPG – a multilateral consultative body among 31 member countries – the NCG is a bilateral consultative body between South Korea and the U.S. Only a few countries such as the U.S. or the U.K. have a say in the NPG, but South Korea will have more leverage in leading the dialogue and reflecting its opinions in the new NCG as a bilateral structure.

Korean Type Nuclear Sharing?

Meanwhile, the Washington Declaration and the launch of the NCG have sparked controversy over whether a realistic and practical nuclear-sharing arrangement is feasible between South Korea and the U.S. Under the NPG, the U.S. practices a nuclear sharing arrangement with its NATO allies but in actuality, the U.S. does not allow joint control of its nuclear assets. Edgard Kagan, Senior Director for East Asia and Oceania at the National Security Council claimed that the basis for nuclear sharing is the “control of weapons," which is somewhat distant from reality. This is because NATO allies have no practical power to control (not to speak of authorize) the use of U.S. nuclear weapons. As the U.S. has deployed tactical nuclear weapons in five NATO member countries - Italy, Germany, Turkey, Belgium, and the Netherlands, these five European allies can exercise some control over the transport and management of the deployed nuclear weapons. Although NATO forces practice drills with strategic bombers carrying tactical nuclear weapons, the U.S. has the sole authority over the use of its nuclear weapons. The permanent deployment of U.S. nuclear weapons in the region may be an advantage, but in the end, the key will be how much say the European allies have in the final decision to use the nuclear weapons. Similarly, with the establishment of the ROK-U.S. NCG, what matters more is the extent to which South Korea can be involved in U.S. nuclear operations of nuclear weapons in the future.

Conclusion

The Washington Declaration opened the way for South Korea and the U.S. to institutionalize strengthened extended deterrence. Through joint planning and training, and incorporation of Korea’s conventional weapons support for US nuclear operations, the Korea-US alliance would be able to strengthen deterrence capabilities to a level different from the past through the concretization of ‘Korean-style extended deterrence’ that Korea and the US would work together on. At a time when neither South Korea’s nuclear armament nor redeployment of U.S. tactical nuclear weapons is a realistic option, the current government’s decision seems to be the most reasonable and rational choice. Upon insufficient grounds, some argue that South Korea has renounced its nuclear sovereignty by reaffirming its longstanding commitment to its obligations under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in the Washington Declaration. Rather, South Korea reaffirmed its commitment as an exemplary country under the Treaty. The Washington Declaration is just a stepping stone. By implementing follow-up measures with the U.S., the Yoon administration must build on the new extended deterrence system that is concrete and substantial enough for the Korean people to realize the results of the Washington Declaration.