Five things you need to know about one of the world's most dangerous places.
TAIPEI, Taiwan — It's a 3.5 million-square kilometer stretch of ocean, speckled with some 200 coral atolls, some submerged or so tiny they hardly deserve to be called islands.
Welcome to the South China Sea, an obscure patch of global real estate that you're likely to hear more about in coming years.
Six Asian countries have long had competing — at times comical — claims to various islands here, sending token military forces to occupy barren rocks at great expense in the name of national pride.
What's new is China's muscle-flexing, which, if trends continue, could make the South China Sea one of Asia's most dangerous flash-points.
Fueling tensions in the sea are untapped oil and natural gas reserves, China's growing strategic interest in protecting sea lanes by which it gets some of its oil, and Beijing's desire to develop a "blue-water" navy capable of projecting power far beyond China's shores.
The U.S. is paying closer attention to the South China Sea, after China reportedly threatened U.S. energy firm ExxonMobil with retaliation if it continued oil exploration off Vietnam in waters China considers its own. And last year Chinese military vessels harassed U.S. surveillance ships in the sea.
Earlier this month, U.S. Defense Secretary Robert Gates made what's believed to be the highest-level public U.S. remarks to date on the issue.
"The South China Sea is an area of growing concern," he said at a security forum in Singapore. "This sea is not only vital to those directly bordering it, but to all nations with economic and security interests in Asia."
Gates repeated the U.S.' longstanding policy that it takes no position on conflicting sovereignty claims in the South China Sea.
But he said the U.S. believes "it is essential that stability, freedom of navigation, and free and unhindered economic development be maintained" and that "we object to any effort to intimidate U.S. corporations or those of any nation engaged in legitimate economic activity."
Here's a primer on the issue:
1) Why does America care?
The U.S. objects to any attempts to intimidate American energy companies operating in the South China Sea, which stretches from China all the way south to Indonesia. It also insists on the right of free navigation in international waters, defined, in accordance with customary international law, as any waters beyond 12 nautical miles from a nation's shoreline.
China says its sovereign territorial waters extend 200 miles from its shores, and makes a historical claim to almost all of the South China Sea, according to a backgrounder from the Heritage Foundation. China also says that any ship traversing the sea should first obtain Chinese permission. It has long complained about U.S. intelligence-gathering from spy-planes and spy-ships operating off its coastline.
2) Who else claims territory in the South China Sea?
Taiwan, Vietnam, the Philippines, Malaysia and Brunei also claim all or some of the South China Sea. Vietnam and China both claim the Paracels islands (known as the Xisha in Chinese), which China has controlled since a 1974 battle with Vietnam that left 18 dead. The other four countries as well as China and Vietnam also claim some or all of the Spratly Islands (known as the Nansha in Chinese) further south.
China's hold here is more tenuous; a skeleton force occupies nine speck-like islands, while Taiwan holds the largest island Itu Aba (or Taiping island, in Chinese), Vietnam holds 29 islands, the Philippines eight and Malaysia three, according to Michael Richardson, a visiting researcher at the Institute of Southeast Asian Studies, in a recent commentary. More than 70 Vietnamese sailors died in the latest military clash in the Spratlys, with China in 1988.
3) What's new about China's behavior?