International Security 28.4 (2004) 125-160
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Strangulation from the Sea?
A PRC Submarine Blockade of Taiwan
Michael A. Glosny
The rise of the People's Republic of China (PRC) is one of the most important challenges for U.S. foreign policy.1 Although many scholars judge current U.S.-China relations to be at their best in many years, President Chen Shui-bian's moves toward gradual independence before Taiwan's March 2004 presidential election, which were met by warnings and threats from the mainland, are a reminder that the Taiwan issue remains a potential source of instability.2 Further moves toward Taiwan's independence during President Chen's second term, such as rewriting the constitution, may very well lead to another Taiwan Strait crisis. The military buildup of the People's Liberation Army (PLA), which is largely focused on Taiwan, combined with the island's disputed political status, make a PRC attack on Taiwan one of the most likely short-to-medium-term (next five to ten years) threats to East Asian stability, and therefore U.S. economic and security interests.3 Could the PRC successfully use military force to settle the Taiwan issue?
Scholarly debates about Chinese intentions and overall strategic goals in East Asia rarely address the prospects for a successful Chinese use of force [End Page 125] against Taiwan.4 Although there has been much research on the PLA and the cross-strait military balance, these works usually do not provide an analysis and evaluation of a China-Taiwan force encounter.5 To assess the prospects for a successful use of force, one needs to analyze a particular tactic or combination of tactics that China might use and Taiwan's potential responses.
Although two recent analyses suggest that a PLA amphibious invasion would be unlikely to succeed before 2010, they also suggest that in the short to medium term, the PRC is more likely to attempt to coerce Taiwan than it is to launch an invasion.6 Without sufficient military capability to conquer Taiwan, the PRC would have to rely on inflicting enough damage to force capitulation.7 The PLA's recent modernization efforts seem to focus on developing coercive [End Page 126] capabilities.8 The two most widely discussed coercive strategies are the use of short-range ballistic missiles and submarines.9 This article focuses on the coercive use of submarines against Taiwanese shipping.10
Several recent books by PLA officers discuss a submarine blockade as a potential force option.11 The PLA is also directing much of its force modernization on advanced submarine procurement and training.12 Moreover, the use of submarines to blockade Taiwan would be relatively easy and would not require development of significant power projection capabilities. According to conventional wisdom in the United States, a submarine blockade could represent a real threat to Taiwan's security.13
This article assesses the prospects for a successful coercive submarine blockade of Taiwanese ports.14 Judging success in a coercive campaign requires both an analysis of the effect of military capabilities and an analysis of Taiwan's [End Page 127] political will. The military analysis seeks to determine how much damage a Chinese submarine blockade could do to the Taiwanese economy. It considers scenarios using torpedoes and those using sea mines. The military analysis employs relatively simple models, based on optimistic and pessimistic assumptions, to determine a plausible range of military damage. The political analysis seeks to evaluate whether the amount of damage inflicted by the submarines would likely be enough to force Taiwan to capitulate. This analysis does not include U.S. military involvement in countering the blockade, though it does include U.S. nonmilitary support. Examining Taiwan's self-defense capability, under conditions of limited U.S. assistance, represents a hard test.
The central finding of this analysis is that although a PRC submarine blockade could impose costs on Taiwan, the threat of a successful blockade is overstated. Even using assumptions very favorable to the PLA Navy (PLAN), a blockade would likely inflict only limited damage on Taiwan. Unless this...