Key point: Avoiding nuclear use could be tricky, but conventional weapons would still kill thousands.

How does the unthinkable happen? What series of events could lead to war in East Asia, and how would that war play out?

The United States and China are inextricably locked in the Pacific Rim’s system of international trade. Some argue that this makes war impossible, but then while some believed World War I inevitable, but others similarly thought it impossible.

In this article I concentrate less on the operational and tactical details of a US-China war, and more on the strategic objectives of the major combatants before, during, and after the conflict. A war between the United States and China would transform some aspects of the geopolitics of East Asia, but would also leave many crucial factors unchanged. Tragically, a conflict between China and the US might be remembered only as “The First Sino-American War.”

How the War Would Start

Fifteen years ago, the only answers to “How would a war between the People’s Republic of China and the United States start?” involved disputes over Taiwan or North Korea. A Taiwanese declaration of independence, a North Korean attack on South Korea, or some similar triggering event would force the PRC and the US reluctantly into war.

This has changed. The expansion of Chinese interests and capabilities means that we can envision several different scenarios in which direct military conflict between China and the United States might begin. These still include a Taiwan scenario and North Korea scenario, but now also involve disputes in the East and South China Seas, as well as potential conflict with India along the Tibetan border.

The underlying factors are the growth of Chinese power, Chinese dissatisfaction with the US-led regional security system, and US alliance commitments to a variety of regional states. As long as these factors hold, the possibility for war will endure.

Whatever the trigger, the war does not begin with a US pre-emptive attack against Chinese fleet, air, and land-based installations. Although the US military would prefer to engage and destroy Chinese anti-access assets before they can target US planes, bases, and ships, it is extremely difficult to envisage a scenario in which the United States decides to pay the political costs associated with climbing the ladder of escalation.

Instead, the United States needs to prepare to absorb the first blow. This doesn’t necessarily mean that the U.S. Navy (USN) and U.S. Air Force (USAF) have to wait for Chinese missiles to rain down upon them, but the United States will almost certainly require some clear, public signal of Chinese intent to escalate to high-intensity, conventional military combat before it can begin engaging Chinese forces.

If the history of World War I gives any indication, the PLA will not allow the United States to fully mobilize in order to either launch a first strike, or properly prepare to receive a first blow. At the same time, a “bolt from the blue” strike is unlikely. Instead, a brewing crisis will steadily escalate over a few incidents, finally triggering a set of steps on the part of the US military that indicate to Beijing that Washington is genuinely prepared for war. These steps will include surging carrier groups, shifting deployment to Asia from Europe and the Middle East, and moving fighter squadrons towards the Pacific. At this moment, China will need to decide whether to push forward or back down.

On the economic side, Beijing and Washington will both press for sanctions (the US effort will likely involve a multilateral effort), and will freeze each others assets, as well as those of any co-belligerents. This will begin the economic pain for capital and consumers across the Pacific Rim, and the rest of the world. The threat of high intensity combat will also disrupt global shipping patterns, causing potentially severe bottlenecks in industrial production.

How do the Allies Respond

Whether US allies support American efforts against China depends on how the war begins. If war breaks out over a collapse of the DPRK, the United States can likely count on the support of South Korea and Japan. Any war stemming from disputes in the East China Sea will necessarily involve Japan. If events in the South China Sea lead to war, the US can probably rely on some of the ASEAN states, as well as possibly Japan. Australia may also support the US over a wide range of potential circumstances.

China faces a less complicated situation with respect to allies. Beijing could probably expect benevolent neutrality, including shipments of arms and spares, from Russia, but little more. The primary challenge for Chinese diplomats would be establishing and maintaining the neutrality of potential US allies. This would involve an exceedingly complex dance, including reassurances about Chinese long-term intentions, as well as displays of confidence about the prospects of Chinese victory (which would carry the implicit threat of retribution for support of the United States).

North Korea presents an even more difficult problem. Any intervention on the part of the DPRK runs the risk of triggering Japanese and South Korean counter-intervention, and that math doesn’t work out for China. Unless Beijing is certain that Seoul and Tokyo will both throw in for the United States (a doubtful prospect given their hostility to one another), it may spend more time restraining Pyongyang than pushing it into the conflict.

War Aims

The US will pursue the following war aims:

1. Defeat the affirmative expeditionary purpose of the People’s Liberation Army Navy (PLAN).

2. Destroy the offensive capability of the PLAN and People’s Liberation Army Air Force (PLAAF).

3. Potentially destabilize the control of the CCP government over mainland China.

Except in the case of a war that breaks out on the Korean Peninsula, the first task involves either defeating a Chinese attempt to land forces, or preventing the reinforcement and resupply of those troops before forcing their surrender. The second task will require a wide range of attacks against deployed Chinese air and naval units, as well as ships and aircraft held in reserve. We can expect, for example, that the USN and USAF will target Chinese airbases, naval bases, and potentially missile bases in an effort to maximize damage to the PLAN and PLAAF. The third task probably depends on the successful execution of the first two. The defeat of Chinese expeditionary forces, and the destruction of a large percentage of the PLAN and the PLAAF, may cause domestic turmoil in the medium to long term. US military planners would be well-advised to concentrate the strategic campaign on the first two objectives and hope that success has a political effect, rather than roll the dice on a broader “strategic” campaign against CCP political targets. The latter would waste resources, run the risk of escalation, and have unpredictable effects on the Chinese political system.

The PLA will pursue these ends:

1. Achieve the affirmative expeditionary purpose.

2. Destroy as much of the expeditionary capability of the USAF and USN as possible.

3. Hurt America badly enough that future US governments will not contemplate intervention.

4. Disrupt the US-led alliance system in East Asia.

The first task requires the deployment of PLAN surface forces, possibly in combination with PLAAF airborne forces, to seize an objective. The second involves the use of submarines, aircraft, cruise missiles, and ballistic missiles to destroy US and allied installations and warships across East Asia.

The third and fourth tasks rest upon the second. The PLA will attempt to inflict sufficient casualties on US forces that future US decision-makers will hesitate to use force against the PRC. Similarly, the survival of the US-led alliance system requires that the United States successfully defeat Chinese aggression; if it cannot, the alliance system could deteriorate and collapse.

The United States hasn’t lost a fighter in action since the 1999 Kosovo War, and hasn’t lost a major warship since World War II. The sinking of a warship would likely also result in the greatest loss of life of any single action for the US military in action since the Vietnam War. However, both US and Chinese strategists may overestimate US casualty aversion. The loss of a major warship and its crew might serve to solidify US commitment (at least in the short term) rather than undermine it.

The “Hold Your Breath” Moments

The biggest moment will come when the PLA makes an overt attack against a US aircraft carrier. This represents the most significant possible escalation against the United States short of a nuclear attack. If China decides to attack a US carrier, the war no longer involves posturing and message sending, but rather a full-scale commitment of capabilities designed to defeat and destroy enemy military forces.

The means for this attack matters. An attack launched from a ship or a submarine makes any PLAN military vessel fair game for the United States, but doesn’t necessarily incur US attacks against PLAAF airbases, Second Artillery missile installations, or even naval installations.

The most dangerous form of attack would involve a ballistic missile volley against a carrier. This is true not simply because these missiles are difficult to intercept, but also because such missiles could carry nuclear warheads. The prospect of a nuclear state using a conventional ballistic missile against another nuclear state, especially one with a presumptive nuclear advantage, is laden with complexity.