executive summary: This article considers the challenges facing South Korea and Singapore in the event of a Chinese invasion of Taiwan and concludes from these case studies that, despite their track records of security cooperation with the U.S., both will need to adopt a nuanced, calibrated response to such a contingency. main argument Increasing Sino-U.S. rivalry underscores the contingent scenario of a clash over the Taiwan Strait as a low-probability but high-impact event that would pose difficult questions for secondary states in the Indo-Pacific, such as South Korea and Singapore. Although South Korea and Singapore can in theory opt out of a U.S.-led intervention should China attempt to invade Taiwan, this course of action would be strategically imprudent. Yet, the extent to which they would be able to contribute to a U.S.-led intervention is limited. Rather than contemplate a material contribution of military forces to a U.S.-led intervention in a cross-strait contingency, it would be more realistic for South Korea and Singapore to adopt a calibrated approach, albeit with different focuses: South Korea, as a formal U.S. ally, would be anchored in limited military and logistical contributions within the alliance framework, whereas Singapore, as a non-allied U.S. security partner, would exercise greater diplomatic autonomy through a norm-based, legalist approach. Such even-handed responses offer the best prospect of simultaneously signaling to Beijing that an unprovoked invasion of Taiwan is against China's interests, while also indicating to Washington that it should not take security cooperation with U.S. allies in the Indo-Pacific for granted. policy implications • Given possible shifts in U.S. priorities during a Taiwan Strait contingency, South Korea should strengthen its independent defense capabilities and clearly define the scope and conditions of strategic flexibility for U.S. forces on the Korean Peninsula. • In light of possible divergence between U.S. and Singaporean interests in a Taiwan Strait contingency, Singapore should strengthen its indigenous defense industries in areas where it enjoys economies of scale, while simultaneously indicating, albeit tacitly, that Washington should not take Singapore's willingness to cooperate for granted. • South Korea and Singapore should deepen integration within Indo-Pacific frameworks, such as the Indo-Pacific 4 and the Five Power Defence Arrangements, as well as strengthen regional diplomatic and security architecture with like-minded partners in the European Union and NATO.
Tan et al. (Thu,) studied this question.