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If China invaded a U.S. ally or partner, even a small number of U.S. ground troops could help local forces mount a determined resistance. Modern conflicts in Southeast Asia and the Middle East have demonstrated what a modest irregular ground force can achieve with the help of modern weapons and capable advisers. Thanks to U.S. advisers and airpower, an overmatched South Vietnamese army was able to withstand a full-scale assault by North Vietnamese forces in 1972. Nearly three decades later, in 2001, a small contingent of U.S. Special Forces, backed by strike aircraft, helped Afghanistan’s Northern Alliance defeat the Taliban. And in 2006, Hezbollah fighters in Lebanon, with the assistance of Iranian advisers, fought the Israeli Defense Forces to a standstill for a month. A similar effort by U.S. ground forces in the Pacific could make seizing and occupying territory an extremely costly proposition for China, especially if local forces also had advanced training and equipment. Access to short-range, precision-guided mortars, rockets, and shoulder-fired antiaircraft missiles, for example, would maximize the lethality of small guerrilla resistance units.
By shouldering greater responsibility for denying the PLA the air and sea control it needs to mount offensive operations, ground forces could liberate U.S. and allied air and naval forces to perform the missions only they can accomplish, such as long-range surveillance and air strikes. Should deterrence fail, these air and naval assets would prove critical to defending the first island chain and offsetting PLA advantages. For example, the PLA can concentrate forces at any point along the first island chain far more rapidly than can the United States and its allies, whose militaries are more widely distributed. And it doesn’t have to reconcile conflicting national interests. (In the wake of a Chinese offensive against a single island, countries along the chain would likely want to keep their forces in place to defend their homelands.) By reducing the demands on U.S. air and naval forces for such missions as air and sea denial, ground forces would enable these air and naval forces to stand in reserve, ready to move quickly to defend a threatened link in the chain.
To be successful, a policy of deterrence also needs to have a credible threat of retaliation after the fact, and here, too, ground forces could help. At present, the U.S. weapons that can launch a precise retaliatory strike are located on increasingly vulnerable forward air bases and aircraft carriers. The Pentagon plans to address this problem in part by building new submarines and long-range stealth bombers, but the cost of such hardware is high, especially given their relatively modest payloads. Ground forces, by comparison, may offer a cheaper way to provide additional firepower. Unlike air and naval forces, ground forces do not need to return to distant bases in order to rearm. They can store far more munitions than even the largest bomber or warship, and they can place them in hardened bunkers that are better shielded from attack.
Moreover, in the event of a conflict, the PLA would benefit from a particularly asymmetric advantage: its large force of land-based intermediate- and medium-range ballistic missiles. The United States, as a signatory to the Intermediate-Range Nuclear Forces Treaty, cannot deploy these systems. Yet by equipping ground forces with comparatively inexpensive missiles that conform to the treaty’s range limitations, and by positioning them forward along the first island chain to reduce the cost associated with delivering missiles over extended ranges, Washington and its allies could go a long way toward fixing the imbalance at a relatively low cost. And if ground troops could not physically maneuver rapidly enough to respond to a breach in the island chain’s defenses, those nearby could quickly respond by concentrating their missile fire on the threatened area.
Perhaps the first island chain’s greatest vulnerability is the U.S. battle network—the critical systems that handle everything from directing and tracking troops and supplies to guiding weapons. This network currently relies heavily on satellites and nonstealth unmanned aerial vehicles, both of which the PLA could target. The best way to reduce that risk would be to establish a communications network of fiber-optic cables buried beneath the ground and the seabed along the chain, allowing disparate forces to safely receive and transmit data from hardened command centers on land. Island-based air defense and sea-denial forces, as well as antiship minefields, could protect the cable lines running between the islands.
THE ART OF THE POSSIBLE
As with any operational concept, Archipelagic Defense faces hurdles. Two of the most prominent are fiscal and geopolitical: the prospective cost and the willingness of states along the first island chain to cooperate. But despite the price tag of a new posture, the defense community in the United States is beginning to realize that current projected cuts in the Pentagon’s defense budget do not square with today’s increasingly dangerous security environment. The National Defense Panel, a bipartisan group of U.S. defense experts, recently recommended that the Obama administration and Congress restore defense spending to the levels projected in the Pentagon’s original budget for fiscal year 2012. Adopting that recommendation would substantially increase the Pentagon’s resources over the next decade.
The Pentagon can also make the argument that investing in Archipelagic Defense could yield future returns beyond the western Pacific. For example, the so-called AirLand Battle concept, which was developed in the 1970s and helped deter a Warsaw Pact attack on NATO, succeeded not only in central Europe; the United States and its allies also relied on it, in modified form, during the 1990–91 Persian Gulf War. Similarly, the Pentagon could employ many of the capabilities associated with Archipelagic Defense to defend other critical regions, including allies and partners near the Persian Gulf and the Baltic Sea.
If the Defense Department cannot secure budget increases, it can still make changes to better match its overall posture to the current security environment. To cite but one example, the Pentagon still earmarks a significant number of ground forces to defend South Korea from a North Korean attack. Yet a large-scale invasion is unlikely; the greater threat is that Pyongyang could launch a strike with missiles armed with nuclear or chemical warheads. In any event, South Korea has a population that is twice as large as its enemy’s and a per capita income that is more than 15 times as large. Seoul can and should shoulder a greater portion of the burden of its own defense against a traditional ground invasion.
Even with the right resources, dealing with a welter of regional allies and partners will undoubtedly prove challenging. U.S. ground forces would have to play different roles depending on the country. Japan, with formidable capabilities of its own, could bolster its ground defenses without much U.S. support. By contrast, U.S. ground forces would probably need to take on a larger role in the Philippines. In both countries, a greater U.S. ground presence would provide a level of assurance that air and maritime forces, which can be quickly withdrawn, cannot. Taiwan, meanwhile, given the absence of diplomatic relations with the United States, would have to act with little or no assistance.
Several countries, Japan and Vietnam in particular, have already suggested that they are serious about fielding the kind of robust defenses that would be required for Archipelagic Defense. Other states beyond the first island chain, including Australia and Singapore, appear inclined to provide basing and logistical support. But just as it took NATO well over a decade to establish a formidable conventional deterrent to the Warsaw Pact, the United States and its allies cannot establish Archipelagic Defense overnight.
Committing to the strategy now would have the advantage of allowing Washington and its friends to spread the expense of fielding such forces over time. In the meantime, given the region’s ongoing military competition, the United States and its allies along the first island chain must make a persistent, sustained effort to preserve regional stability and prosperity. Of course, Archipelagic Defense would provide no more of a panacea against all forms of Chinese aggression than NATO’s conventional deterrent solved the problems once posed by Moscow’s wars of national liberation and nuclear buildup. But establishing such a posture would represent an essential—and long-overdue—first step in counterbalancing China’s revisionist ambitions.
