Here on Hainan Island, on the northern edge of the sea, China bases its nuclear submarines, including the four equipped to launch ballistic missiles. China's problem is that it is hemmed in. Its coastline consists of the Yellow Sea, the East China Sea, and the South China Sea -- which means its only access to the Pacific and beyond is through relatively narrow straits bordered by Japan, the Philippines, Singapore, Malaysia or Indonesia.
Brad Glosserman, of the Honolulu office of the Center for Strategic and International Studies, suggests that one reason China is promoting its claim to most of the land features in the South China Sea against its most vocal rivals -- Vietnam and the Philippines -- is a desire to push the U.S. Navy out of the area.
Even before this week's news about the American proposal to sharply step up naval patrols around the artificial islands China is constructing in the sea, American vessels and planes have been regularly tracking the subs, something that China is not at all happy about. China is "most concerned" about U.S. intelligence gathering in the South China Sea, Wu Shicun, president of the National Institute for South China Sea Studies here, told a group of foreign journalists Wednesday. The journalists were on a tour sponsored by the East-West Center of Hawaii.
If Beijing could effectively keep the reconnaissance at bay by establishing its sovereignty over most of the sea at the expense of its neighbors, Glosserman says, that would clear the way for the subs to ease out into the Pacific without being so obvious about it.
For the record, Chinese defense and foreign affairs officials say China has no intention of restricting navigation or overflights, as long as they are conducted "in accordance with international law." But Zhou Bo, a senior colonel at the defense ministry's foreign affairs office, said Tuesday that that would still leave China and the United States at loggerheads because they interpret international law on the matter quite differently.
There is, in any case, another way of looking at the submarine factor. Nuclear submarines are intended as a deterrent to nuclear war. China's subs have no practical value in its disputes with Vietnam and the Philippines. Almost the only reason to have them is to deter an American attack. (India's nuclear weapons are also a consideration for Beijing.) Submarines are less vulnerable than land-based intercontinental ballistic missiles or nuclear bombers -- and that makes them the most valuable leg of any nation's deterrent arsenal.
China's problem is this: Its nuclear subs are too noisy to avoid detection. So China has to figure out an operational routine, even in peacetime, that makes sense. The boats can't spend all their time in port, because any sudden deployment in a crisis would tip China's hand. They can't cruise the high seas, because the United States military would be able to follow their every move.
Tong Zhao, an analyst at the Carnegie-Tsinghua Center for Global Policy in Beijing, thinks China may have decided on a "bastion" policy, with the South China Sea as the bastion. If by enforcing its claims to sovereignty Beijing could turn the sea essentially into a Chinese lake, guarded by surface vessels and aircraft, and that would give the subs some protected room to maneuver, Zhao says.
It's akin to a Cold War Soviet strategy, but with a few key differences. The Soviets could put their subs in the remote seas that border the Arctic Ocean, where they could take advantage of the ice cover, and where there was no commercial shipping to get in the way. The South China Sea, in contrast, carries 80 percent of China's overseas trade, and as much as half of all global tanker shipments. It is bordered by less than obedient neighbors, which are quite happy to host American and Indian naval operations. Denying access to the U.S. and other navies would require, as the Soviets found, an expensive deployment of conventional surface ships.
And, in a place like the busy South China Sea, that would only increase the chances of a confrontation between conventional forces, Zhao says. "All in all, the South China Sea is becoming increasingly crowded."
American navy officials say that, as important as the Chinese submarine fleet is to Beijing, they don't think it's the principal driver of Chinese policy in the South China Sea. Their Chinese counterparts would appear to agree.
It's not about strategic considerations, Capt. Tian Shichen, of the defense ministry's information office, told the visiting journalists Tuesday. "It's our own territory. We need to defend it." And it doesn't get any more complicated than that, he said, as much as China's neighbors might dispute the assertion.