After years of friction over offshore oil and gas stakes, China has plunged into a new series of diplomatic confrontations over the disputed South and East China seas, and analysts expect the tension to continue drawing in the United States.

Beijing, driven in part by the politics surrounding a once-a-decade leadership transition, has lashed out at neighboring Japan and the Philippines. Over the weekend, the official Chinese military newspaper accused the United States of stirring up war. Contributing to the atmosphere, China and the United States are conducting separate naval exercises in the area, and last week, India test-fired a long-range missile that it explicitly depicted as a demonstration of its ability to strike China's largest cities.

Analysts say the prospect of a war in the region is still remote. But unease persists because of Chinese politics, which continue to be roiled by the implosion of a senior party official, Bo Xilai, and the coming change of Beijing's top leadership. Chinese public opinion appears to be galvanizing around the support of a military response to the friction with its neighbors, analysts say, thus reducing Beijing's maneuvering room short of appearing to be weak.

"When [the Chinese] are internally preoccupied and, even worse, divided, they tend to go even harder on these sovereignty issues because they have a tendency to think that other people might be taking advantage of their distraction," said Chris Johnson, a former Central Intelligence Agency analyst on China and now a fellow at the Center for Strategic and International Studies.

For decades, the South and East China seas, while a route for much of the world's seaborne trade, have also been the object of much interest in oil and gas drilling. Emotions have become extraordinarily overheated over multiple overlapping claims to many of the seas' couple of hundred largely obscure and uninhabited islands, including the Spratly and Paracel chains.

Together, more than 100 billion barrels of oil in addition to natural gas may lie near and around the islands in the two seas, according to U.S. and other outside estimates. To date, companies have proven relatively little of the reserves, but there have been sufficient hydrocarbons to motivate current drilling and exploration near Vietnam, the Philippines and elsewhere since, if there are large volumes, no one wants to be left out of the bonanza.

Underlying the trouble is a basic of modern land grabs -- one country, say, the Philippines, asserts the rights to an island, in addition to a 200-mile exclusive economic zone, and others can lose considerable elbow room. As for China, it claims sovereignty over virtually all islands in the South China Sea, along with territory in the East China Sea. "If you have a thousand islands that you claim, your economic zone can be 100,000 square kilometers," says Kang Wu, a senior fellow at the East-West Center in Honolulu.

The current strains go back to September 2010, when Japan arrested a Chinese trawler captain who repeatedly rammed a Japanese Coast Guard cutter near a disputed set of East China Sea islands that Japan calls the Senkaku chain. In response, China canceled diplomatic meetings, severed Japan's supply of rare earth elements -- which are crucial to high-tech gadgetry -- and threatened worse if the captain was not let go and an official apology was not made.

Relations were somewhat restored after much Japanese diplomatic groveling -- until last week. On April 16, a fresh row erupted when Shintaro Ishihara, the governor of Tokyo, announced that the municipal government would buy the Senkakus from its current private owner. China has bitterly protested Ishihara's stated plans, insisting that it enjoys full territorial rights to the chain.

Meanwhile, though, the Senkaku confrontation has roiled the neighborhood, in which several nations have their own territorial disputes with Beijing. China has challenged oil and gas drilling by India in Vietnam, and oil exploration by the Philippines near its shores.

For the past two weeks, Chinese and Philippine ships have been in a standoff near Scarborough Shoal, an island chain claimed by both nations. Over the weekend, China sought to reduce tension by withdrawing two of three surveillance ships it had deployed at the islands. But in separate interviews yesterday, senior Philippine officials asserted that China's territorial policy threatens the regional economy. The Associated Press, citing an interview on ABS-CBN TV, quoted Philippine Foreign Secretary Albert Del Rosario as asserting that China is attempting to "set the rules for anybody." "I think the current standoff is a manifestation of a larger threat to many nations. They should be concerned if they're interested in maintaining the freedom of navigation and unimpeded commerce," del Rosario told the Manila-based TV network.

A warning to the U.S.

The Obama administration has effectively interceded on the side of China's neighbors by insisting on a regionwide settlement of the disputes, saying that it is most concerned about freedom of navigation.

But over the weekend, the Chinese military issued a blunt warning to the United States on the pages of its official mouthpiece, the Liberation Army Daily. The commentary criticized a current joint U.S.-Philippine naval drill, which started yesterday in the South China Sea.

"Anyone with clear eyes saw long ago that behind these drills is reflected a mentality that will lead the South China Sea issue down a fork in the road towards military confrontation and resolution through armed force," the paper said, quoted by Reuters. "Through this kind of meddling and intervention, the United States will only stir up the entire South China Sea situation towards increasing chaos, and this will inevitably have a massive impact on regional peace and stability."

Notwithstanding such remarks from the People's Liberation Army, Beijing -- broadsided by the region's readiness to defy China and side with the United States -- has appeared to scale back its sharper rhetoric since the 2010 dispute with Japan. Yet no one seems to expect a reduction in its actual territorial claims, nor anyone's in the East and South China seas.

Analysts worry about the timing of the harsh exchanges, coinciding with an extremely delicate period in China. The greater the tension, the more difficult it is for Communist Party leaders to restrain their more hawkish elements in the military, as well as heightened emotion in the population. Yet hope is building around the establishment of a "code of conduct" governing activities such as oil and gas drilling on the seas.

"The bad news is the situation is very messy because of the competition for resources, and because of high prices we are likely to see more friction," said Bo Kong, a professor at Johns Hopkins University. "However, there is some good news: Over the past couple of years, we have started to see a willingness to move toward a code of conduct. I don't know what the ultimate configuration will look like. [But] I believe diplomats have the capability of working out all that language."