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South China Sea Scenarios

In South China Sea scenarios, it is usually assumed that China attempts to use its possession of disputed islands (in particular, the Paracel and Spratly Islands, as well as Scarborough Shoal) in the South China Sea to exert control over neighboring states that are allied with the United States. In such an event, either China or the United States could initiate armed conflict. Some observers have suggested that China could initiate a strong surprise attack to cripple U.S. military bases in the western Pacific with ballistic and cruise missiles; conflict could also arise if a country such as the Philippines or Vietnam asked the United States for aid during a crisis with China.12 Conflicts over control of the South China Sea would most likely involve control of the disputed islands in the region, as well as the degree to which U.S. and Chinese forces could prevent each other from operating effectively within the theater.

A combination of many factors, including the geography of the South China Sea theater and the types of Chinese forces located there, would make any conflict in the region challenging for the United States:

  • China currently exercises de facto control over several of the disputed islands and has been rapidly converting them into military outposts capable of projecting power throughout the theater, which is relatively close to the Chinese mainland. The so-called first island chain, stretching from Japan to Taiwan, the Philippines, and the Indonesian archipelago, could allow countries surrounding the South and East China Seas to isolate China from maritime access to the rest of the world (see Figure 1-2). Although much of the island chain is composed of countries allied with the United States, U.S. military presence in the region is modest and mostly concentrated around the East China Sea in the north. China has spent decades investing heavily in its navy, as well as in cruise and ballistic missiles. Chinese forces on the mainland could credibly attack U.S. air bases anywhere in the region with ballistic missiles and could threaten naval forces within much of the theater. The Chinese have domestic versions of modern air defense systems similar to the Russian S-300 series and have purchased Russian S-400 series air defense systems. Efforts to use U.S. airpower in support of U.S. naval operations would be quite dangerous until U.S. forces successfully suppressed Chinese air defenses. With ASMs and air defenses located on the militarized islands, China could deny U.S. air and naval forces access to almost the entire South China Sea (see Figure 1-2). U.S. forces would have limited ability to destroy or seriously degrade China’s power projection over the South China Sea without striking the Chinese mainland directly, which China could view as highly escalatory. There is no feasible scenario in which the United States could use its ground forces to invade the Chinese mainland to accomplish its objectives in such a conflict.

The United States would thus have few options to prevent China from asserting control over the South China Sea, other than to seize the disputed islands and attempt to destroy enough Chinese air and naval forces that China would accept the new status quo. Such an attempt would be highly risky for U.S. forces because it would have to be undertaken by U.S. air and naval forces that would be highly vulnerable to Chinese A2/AD systems in the theater. The sheer number of Chinese ASMs, as well as the difficulty involved in destroying ground-launched ASMs, would probably make it impossible for U.S. naval forces to operate freely in the western half of the South China Sea.

At the same time, however, China would have limited ability to project power beyond the first island chain. One possible outcome of a conflict in the South China Sea is mutual denial, in which the United States and China each prevent the other from operating freely. Alternatively, because any South China Sea scenario would almost certainly involve other countries in the region (such as Japan, Taiwan, the Philippines, Vietnam, or Singapore), another possible outcome might hinge on China’s ability to coerce those countries to concede their claims to disputed islands, refuse to cooperate with the United States, or in some other way accede to Chinese regional dominance.

Although Chinese air, naval, and missile forces would make a traditional close blockade of Chinese ports a difficult military task, the geography of the South China Sea requires Chinese shipping to pass through several choke points to access overseas markets.

  • Northern routes that head toward North America. These routes pass by three treaty allies of the United States—Japan, South Korea, and Taiwan. The United States has many bases in this region capable of projecting power into the surrounding waters.
  • Central routes that pass through the Philippine archipelago. Chinese claims to the South China Sea that conflict with Filipino claims to the area are a possible cause of a South China Sea conflict. The United States has a mutual defense treaty with the Philippines, and the Filipino government allows the United States to operate from five air bases there, one of which (Antonio Bautista Air Base) is near one set of Chinese militarized islands.
  • Southern routes that head toward the Indian Ocean. The Strait of Malacca is one of the busiest shipping channels in the world. The United States has a long-standing defense relationship with and Navy presence in Singapore, which is near the Strait. Other routes to the Indian Ocean pass through Indonesian waters, however, and the United States does not have a significant defense relationship with Indonesia.

With sufficient cooperation from local allies, the United States could enforce a distant blockade on Chinese shipping by stationing air and naval forces around those choke points. Such a strategy would face several constraints, however: First, Indonesia is not an ally of the United States and would not be expected to help blockade the southern shipping routes. Second, some allies might choose not to participate in any conflict. Third, some of the bases that the United States would need to enforce a blockade are themselves credibly threatened by Chinese attacks.

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Page last modified: 30-06-2021 18:29:27 ZULU