This week’s summit of the Association of Southeast Asian Nations showed again the scale of sensitivities over the South China Sea with the Philippines objecting to a draft statement saying all sides agreed not to internationalize the maritime dispute.

China has consistently opposed ASEAN’s involvement in rival claims over the South China Sea that involve Vietnam, Taiwan, the Philippines, Malaysia, and Brunei.

Following the summit in Cambodia, Chinese Foreign Ministry Spokesman Qin Gang said an ASEAN Declaration of Conduct over the dispute – or DOC – could help ease tensions.

“China will continue to come back [with] sincere dialogue with ASEAN countries and to fully implement in an effective way the DOC so that all parties can accumulate mutual trust and carry on cooperation and put this issue of South China Sea in good control so that we can work together to safeguard peace, stability, cooperation, and development,” said Gang.

That Declaration of Conduct includes all parties exercising self-restraint by not inhabiting any of the currently uninhabited islands in dispute in the oil-rich sea. Indonesian Foreign Minister Marty Natalegawa says talks are already underway to keep alive Chinese/ASEAN cooperation on the issue.

“The key challenge, of course, now is we must ensure that the situation, on the ground or at sea, does not become not conducive so we must contain a conducive atmosphere so negotiation and dialogue can begin to take place,” said Natalegawa.

So why might China’s new leaders be more willing to consider ASEAN’s role in the dispute?

Professor Xiang Lanxin chairs international affairs studies at Shanghai’s Fudan University. He says Beijing’s outgoing leaders miscalculated how Southeast Asian neighbors would respond to broader Chinese territorial claims.

“They did make huge strategic mistakes. I am talking about diplomatic mistakes. One is the assertion of core interests that cover the South China Sea,” said Lanxin.

He says that led to the mistaken impression in Washington and Hanoi and Manila that Beijing intended to claim all of the South China Sea for itself.

“This is an indication of Chinese great ambition of taking over the South China Sea. That’s not the Chinese plan. It is a mistake,” he said.

He expects China’s new leaders will appeal less to nationalism over the South China Sea, moving away from a narrative that focused on the United States as a declining power trying to maintain its status by repositioning diplomatic, military, and commercial assets in Asia.

“Our leaders frequently use the same argument – basically it is a social Darwinist argument – to try to sell their version of nationalism. That has been a very, very risky business,” he said.

Elizabeth Economy directs Asia studies at the U.S. Council on Foreign Relations. She says the new Chinese leader, Xi Jinping, has a choice between a more Deng-Xiaoping-style domestic focus or a more Hu-Jintao assertiveness in regional affairs and the establishment of China as a naval power.

“This more assertive foreign policy, of course, has helped to raise China’s profile internationally but at the same time has brought it into conflict with its neighbors such as Japan, the Philippines, and Vietnam. So the next set of Chinese leaders faces great opportunity in the China that they have inherited but also a set of very distinct challenges,” said Economy.

U.S. President Barack Obama raised the South China Sea issue during closed-door sessions of the ASEAN summit.

ASEAN Secretary General Surin Pitsuwan says Southeast Asian nations do not want the maritime dispute to interfere with what he calls “positive momentum” on other issues, and the Declaration of Conduct does not prevent member states from pursuing rival territorial claims through other channels if they like.