Tensions in the South China Sea continue to fray this week, as China and a US-led alliance of Asian powers jostle for territory and influence.
As US warships carried out joint exercises with counterparts from Japan and India near Chinese waters on Wednesday, a Chinese observation ship began to shadow an American aircraft carrier from seven to ten miles away, the commander of the US aircraft carrier John C. Stennis told Reuters. A Japanese naval official told reporters on board that the carrier would act as a "decoy," drifting away from the seas near the Okinawan island chain where exercises were taking place.
Last week, a Chinese fighter jet intercepted a US spy plane on reconnaissance over the East China Sea. US officials criticized what it called an "unsafe" intercept, while China's Foreign Ministry demanded an end to "close reconnaissance" in the region.
In a separate incident, Japanese officials said on Wednesday that another Chinese observation ship had entered Japanese waters south of Kyushu island. China cited a UN convention allowing for "innocent passage" of foreign ships in another country's waters. But the move comes just a week after Japan raised its hackles over another Chinese ship's passage within 24 miles of a group of remote islands administered by Japan but claimed by China.
Some $5 trillion in trade passes through the South China Sea in any given year, and it's thought to hold a trove of energy resources. The US Energy Information Administration estimates that 11 billion barrels of oil and 190 trillion cubic feet of natural gas are contained in underwater reserves.
One focal point in territorial disputes is China's "nine-dash line," which envelops several hundred small islands over a 1.4-million-square-mile area. The nine-dash line proclaims Chinese sovereignty over all of them, according to China, although the US considers this invalid under international accord. The United Nations has formed an arbitration panel to help resolve the dispute, but China has suggested it will not adhere to the panel's directions.
China appears to have its sights set on control over a broader region than just the islands, Gregory Poling, director of the Asia Maritime Transparency Initiative at the Center for Strategic and International Studies, told The Christian Science Monitor in March.
"The ultimate Chinese goal in the next few years is less about pushing the US military out of the area (though that is the long-term naval strategy)," he told the Monitor, "but rather about achieving administrative domination of the seas, so other Southeast Asian nations can do little without seeking Chinese permission."
This report contains material from Reuters and the Associated Press.