Ongoing riots around Vietnam have claimed the lives of at least 21 people, mostly Chinese. The protestors are angry about the placement of a massive Chinese oil rig inside Vietnamese waters, and are burning Chinese factories and killing Chinese people to show their displeasure.

Vietnam could be a harbinger of a world of significantly constrained Chinese power

We haven't seen anything like this kind of anti-Chinese sentiment in Vietnam in 35 years. It raises a lot of questions. Why are Vietnamese people so angry about a Chinese oil rig? Could this escalate into some kind of conflict or even outright war between the two countries? And what does a rift between the China and a traditional friend say about the future of politics in conflict-ridden East Asia?

Here are the answers to these questions. Among them: Vietnam's attitude toward China is a bellweather for the rest of East Asia. If it really is turning against Beijing, the rest of the region is likely to make China's rise really difficult.

These riots are about Chinese aggression

China and Vietnam disagree about where to set their maritime borders. Vietnam's interpretation is in line with international law, and China's isn't. China broached Vietnamese territory really aggressively recently, and Vietnamese people protested with their government's consent. Those protests escalated to riots targeting Chinese factories.

That's the short version. Here's the longer one.

What happened is that China installed an oil rig on May 1st in waters that legally belong to Vietnam, but which China claims as its own. China actually claims an enormous swathe of the South China Sea that belongs to several other southeast Asian countries. China is basically alone in seeing this territory as Chinese; its efforts to assert its claim, for example with this oil rig off Vietnam's coast, are a sort of proxy issue for China's ability to get whatever it wants in Asia.

Vietnamese people were furious about the oil rig, and even more so when this video of Chinese boats attacking Vietnamese ones attempting to stop the oil deployment surfaced:

The protests wouldn't have happened without the Vietnamese government's say-so. Like China, Vietnam's Communist government has (somewhat) reformed the country's economy along market lines, but has held on to the reins of political control tightly. According to local reporter Jonathan London, the lack of government condemnation of the anti-China protests is tacit permission for them to keep going.

So far, the riots, likely an unsanctioned outgrowth of the sanctioned protests, have claimed at least 21 lives. They've been focused at Chinese people and factories — clear emblems of China's involvement in Vietnamese life. Weirdly, they've also targeted Taiwanese factories, likely because the protestors confused them with mainland Chinese ones.

People are worrying about a war between China and Vietnam, but the real issue is Vietnam's long-term China policy

So the Vietnamese government is, broadly speaking, OK with anti-Chinese protests — because they're also furious with their nominal friend. This doesn't mean they're likely to go to war, but it does call into question the longevity of Vietnam and China's friendly relationship.

The case for the possibility of war is simple: it's happened before. In the late 70s, Vietnam aligned itself with the Soviet part of the Communist bloc rather than the Chinese one (the two had, at the time, parted political ways). China wanted to punish Vietnam for the deviationism, and they fought a somewhat pointless, but fairly bloody, war in 1979.

That's not likely to repeat itself today. For one thing, China is exponentially more powerful than Vietnam, and so Vietnam knows risking a conflict is risking a crushing defeat. For another, China contributes a lot of money to Vietnam's economy, particularly through tourism. Vietnam wouldn't want to risk losing that.

Finally, as London notes, Vietnam's core leadership — its general party secretary, president, and leader of the National Assembly — have a well-known pro-China tack. "Their loyalty," London writes, "is to the enduring illusion that Beijing is a partner."

In each case, the more aggressive China has been, the more sympathetic to America's regional role East Asian countries have gotten

The big question now isn't whether they reverse that view all of a sudden; it's whether they start to reorient Vietnam's foreign policy away from the idea that it should treat China as a friend rather than an antagonist.

Indeed, most of the other South China Sea countries (including Malaysia and the Phillipines) are furious at China over its aggressiveness in the region, particularly over a set of islands, the Spratlys, that contain significant natural resources. Japan and South Korea are angry over China's moves in the nearby East China Sea.

In each case, the more aggressive China has been, the more sympathetic to America's regional role East Asian countries have gotten. The US navy has built ties with Vietnam gradually since 2012, when Chinese aggression really escalated, and is pushing for more cooperation. "We're talking to US but it is too early to say how the tensions now will change our approach," an unnamed Vietnamese military source told Reuters. "We have a lot to consider."

How Vietnam turning against China could presage a region-wide shift against China, and toward America

Vietnam is a small, not-all-that-powerful country. But it actually does matter if it starts to align with the US and other regional powers, because it suggests that China will have a much tougher time becoming the dominant power in East Asia than many expect.

One of the major theories of China's rise is that East Asian countries will basically accept it without much resistance. This is partly for historical reasons — China had long dominated East Asia in the past — and partly for modern ones. China has put a lot of effort into convincing its potential rivals that it wants to rise peacefully, and given that its rise seems all but assured, it may make sense for East Asian countries to accept that peaceful rise narrative rather than challenge it.

University of Southern California's David Kang made one of the strongest versions of this argument in 2004. China, for Kang, has done an excellent job signaling that it wanted to take its place as the most powerful state in the region without doing harm to other country's territory and/or interests. "East Asian states actually believe China's claims," he writes, "and hence do not fear — and instead seek to benefit from — China's rise."

But take a look at one of the details of Kang's argument: which countries are most likely to be sympathetic to China's rise. It's in the chart below.

See that? Other than North Korea, which is deeply reliant on China for its very survival, Vietnam is the country most likely to peacefully accept China's rise. Given their similar political systems and somewhat entwined history, that makes sense.

That's why it's a huge deal if these protests signify a Vietnamese turn against China. If China has managed to send out signals aggressive to alienate Vietnam, than it has very little hope of doing what Kang predicted it would do: convince the other countries in the region it would make its way up the ladder peacefully.

Here, China's loss is America's gain

Here, China's loss is America's gain. The more friendly countries there are to the United States, the easier it is for the US to coordinate a military-political strategy aimed at preventing Chinese expansion (though even anti-Chinese powers often have important internecine disputes of their own). If China is boxed in by friendly states in East Asia, it will be significantly harder for China to project military power around the world. In essence: Vietnam could be a harbinger of a world of significantly constrained Chinese power.

"Could" is the important word there, though. We don't know how significant these protests are yet, or how the Vietnamese government will decide to rein them in. It's best holding off making confident predictions of a transformation of East Asian power politics for some time.

That said, this has the potential to be a gigantic deal. The world should be paying attention.