What Would Happen in the Hours and Minutes After a US-China War Started?

The US and China aren't allies, but they aren't adversaries either. Relations between the two countries are an uneasy stew of tension and cooperation. Even though China is boosting its military spending and has a history of not respecting the maritime borders of its neighbors, Sino-American relations under President Barack Obama often maintained at least an appearance of bilateral cooperation.

Donald Trump, on the other hand, campaigned on the idea that China is a trickster nation that bamboozled the US on trade by futzing with its currency valuation. Immediately after the election, he risked offending China by talking to the president of Taiwan. Since then, the new administration's stance on China has been unclear at best, and for its part, Beijing is preparing for a trade war, which Trump has all but promised. It's obvious that China is willing to fight the US, at least economically.

But could the US and China come to blows militarily? It's not looking likely, according to M. Taylor Fravel, an associate professor of political science and a China expert in the Security Studies Program at MIT. Fravel explained to me that it's not in China's interest to suddenly declare war on the US. "The worst thing for an autocrat is losing a war," he said. "I do not see the use of force as solving many problems for them."

Still, war with China is something Trump adviser Steve Bannon said was inevitable a year ago. Chalk that up to Bannon's habit of stating things in the most dramatic way possible, but when someone in the White House feels that way, it could drive policy in unanticipated directions.

Even if you set aside the unlikely possibility of an abrupt Pearl Harbor–style surprise attack from either side, tensions could still escalate to the point where shots get fired. Fravel was kind enough to walk me step by step through the potential flash point that could usher in a war between two of the most powerful countries in the world.

The US and China obviously don't share a border, so unless the flash point happens to be North Korea, boots-on-the-ground battlefield scenarios are pretty farfetched. According to a 2015 report prepared by the RAND Corporation for the US Army, "A Sino-US conflict is unlikely to involve large land combat." So we're most likely talking about a conflict between US and Chinese ships, planes, and lots of missiles.

Indeed, if war were to break out, one likely cause would be a "conflict on an island in the South China Sea," Fravel told me. He listed some candidates. A crisis could center on a maritime dispute between China and the Philippines, for instance. "Finally, of course, you have Taiwan," he told me—referring to the island that forms the northernmost limit of the South China Sea. Fravel called Taiwan "the one issue that could spark a large war between the US and China, even though of course that's unlikely."

So we're going to use Taiwan as our example.

Here's a quick recap of the whole Taiwan thing: The island is Chinese soil according to mainland China, but it's an independent country according to its own people. The US used to recognize Taiwan as a country, but since 1979, the official US policy on Taiwan has been that mainland China owns Taiwan on paper, while at the same time, "the United States and Taiwan enjoy a robust unofficial relationship," as the State Department website says. The government of China doesn't like that relationship, which includes arms trading as well as a contentious deal that says the US will help Taiwan defend itself.

With that in mind, Fravel laid out a fateful scenario: "The mainland believes Taiwan is moving toward independence," and it opts to "engage in a very limited use of force to prevent that."

Fravel clarified that "limited use of force" meant that China wouldn't just start bombing Taiwan. Rodger Baker, a VP of strategic analysis at the military think tank Stratfor, concurred. "In most cases," he told me in an email, "the initial path may be trying to limit further conflict," but unfortunately, "while both are seeking to mitigate, their actions could inadvertently lead to escalation."

In a conflict between Taiwan a China, this means a blockade, which Fravel called "an act of war that doesn't involve shooting." According to a 2012 report by the Center for Strategic and International Studies, an attempted blockade against Taiwan would feature China using its superior naval power to divert ships headed to Taiwan into mainland China for an "inspection." Or China could simply declare that it was using Taiwanese shipping routes for military exercises.

This would leave Taiwan cut off from receiving imports, meaning it can't do business, meaning it's in trouble.

"The US is faced with the decision about whether or not to help Taiwan break out of a blockade," Fravel told me. It wouldn't have to defend Taiwan, according to a 2009 op-ed by Richard C. Bush of the Brookings Institution, but President Trump has made his animosity toward China abundantly clear.

Baker agreed that "the US would have a strong incentive to intervene," in a circumstance like this, although he added that "China's anti-ship missiles would potentially delay a strong initial US response."

China's hypersonic anti-ship missiles, also known as "carrier killers," are seriously scary. They're faster than any other missile in the world, meaning no known weapon could intercept one, and as their nickname suggests, they're capable of sinking a US aircraft carrier. (Hawks in the US Congress hate the fact that China has these missiles, by the way.)

Still, despite the threat of sophisticated weapons designed with just this occasion in mind, President Trump could send carriers to escort incoming ships to their Taiwanese destinations. The result: Everyone is on edge.

If everything went to shit, according to Fravel, it could be due to "warning shots being fired by either US or Chinese vessels." The US Navy fires warning shots all the time. In January, for instance, the Navy fired warning shots at Iranian ships, and the Iranian ships changed course.

But a 2013 report by Andrew S. Erickson of the US Naval War College describes a Chinese plan to strengthen a blockade that includes the use of its anti-ship missiles to deliver warning shots. If China doesn't call ahead to say, Hey, so just FYI, we're about to fire a warning shot, Erickson writes, the missiles "could easily be misinterpreted as failed attempts to strike the target. Thus the 'missed' strikes could result in escalation rather than deescalation."

In other words, China could fire a missile just as a show of force, but the US might think it's the start of actual fighting. The US would then launch missiles of its own, likely aimed at disabling further launches.

After that, ships would exchange fire, with missiles going after military targets on both sides. Before long there would be casualties. "Our forces are based in Japan, Korea, Guam, and elsewhere," Fravel told me. "[China] might want to attack those forces before they arrive."

China would now be at war with the world's only military superpower. What's next?

According to the RAND Corporation report, "If either US or Chinese political leaders authorize their military commanders to carry out plans for sharp strikes on enemy forces, a severely violent war would erupt."

It might seem like China's People's Liberation Army would seize on the sudden war scenario and invade Taiwan in an attempt try to reunify what it perceives as a divided country, but Baker doubts this. "The terrain is difficult, the population will not be cooperative, and the potential for a long, drawn out anti-guerilla war would be daunting," he told me.

"The mainland calculation would be that if they launch an amphibious assault in Taiwan, it would almost certainly trigger US involvement, and US involvement would be decisive," Fravel added.

So China wouldn't try to take over any Taiwanese land, and they may just want to maintain their blockade, but they may want more.

In the ensuing days, the fight to maintain China's Taiwanese blockade could evolve into an attempt by China to dominate the South China Sea, a body of water that sees $5 trillion in ship-based trade per year. This would not go well for them. "China, right now, in no way has the capability to do that," Fravel told me. "It's not going to happen in the next year, two, or three."

Indeed, RAND's report on the topic says China should wait a while if it wants a shot at regional maritime supremacy. China, RAND thinks, would be pummeled by the US if this effort had been launched in 2015, and would still probably lose if it waited until 2025. The report adds, "by 2025, though, US losses would increase." But despite being confident that the US would dominate, RAND advises the US military that "it would be far better for stability and at least as good for deterrence for the US military to emphasize, in general, planning for a prolonged high-intensity war."

The result of a prolonged war may not be that the US gets driven out with superior force, but in the end, Fravel suggested, a war for the South China Sea could create a queasy Korean War–style stalemate.

"It would basically be a war over the future of the US in Asia," Fravel told me.

UPDATE 3/22/17: An earlier version of this article misspelled M. Taylor Fravel's name in several places.

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