China has taken new actions that raise the stakes in its disputes with its Southeast Asian neighbors over the islands and atolls in the South China Sea. Taken together, they are but another worrying sign, not only about the prospect of a multilateral agreement between the parties but also about governments in the region and their commitment to negotiate over their competing claims.

Over the weekend, China’s state run news agency Xinhua reported that the People’s Liberation Army would establish a military garrison in Sansha city in order to provide security to the islands it claims in the South China Sea and the waters around them, known as Nansha, Zhongsha and Xisha island in Chinese (also known as the Spratley, Macclesfield Bank and Spratley Islands respectively by their other claimants).

In addition, Xinhua reported that the more than 1,000 residents living on the islands elected a mayor and 45 legislators as their representatives.

The Philippines and Vietnam have long been opposed to China upgrading Sansha to a city and naming elected representatives. The establishment of an army command center on the islands signals that China is willing to defend its claims militarily.

A month ago, China established the city of Sansha, located in Hainan Province on the South China Sea coast, to administer the islands and help strengthen its claims over the entire sea, according to a Chinese official.

Tensions in the region have been steadily rising since China’s assertion of sovereignty over the entire sea in 2010 as well as increasing provocative actions by its naval and fishing ships. This comes against the backdrop of a “rising China” and mounting apprehension in the region about a more aggressive Chinese foreign policy.

The South China Sea is geopolitically important, not only because of the vital sea lanes of communication that pass through it but also because of the vast oil deposits believed located there.

With increasing domestic pressure on governments to not relinquish any sovereignty to the islands, the region has witnessed a game of oneupmanship by countries claiming ownership in the area over the past few months.

Perhaps more disconcerting, these developments come after the annual ASEAN regional forum of foreign ministers last week in Cambodia failed to adopt a “code of conduct” for the South China Sea as well as, for the first time in its 45 year history, failed to pass even a joint communiqué at the conclusion of the meetings.

The Center for Strategic and International Studies think tank, located in Washington DC, said in its report following the ASEAN summit that Cambodia, working in tandem with Chinese representatives to the conference, scuttled the issuance of communiqué because it would have referred to China’s disputes with the Philippines and Vietnam in the sea. CSIS concluded that Chinese policy is now clearly to divide and weaken ASEAN.

I wrote here week that China’s continued heavy handed diplomacy in Southeast Asia will only result in its isolation and an increasing probability of hostilities breaking out. The events this past weekend only strengthen that view.