More South China Sea sabotage

Vietnamese border guards watch the US Seventh Fleet's USS Blue Ridge entering port as Vietnam welcomes the port call of three US naval ships in the central city of Danang on April 23, 2012.</p>

Vietnamese border guards watch the US Seventh Fleet's USS Blue Ridge entering port as Vietnam welcomes the port call of three US naval ships in the central city of Danang on April 23, 2012.

On his recent spin through Southeast Asia, U.S. President Barack Obama urged calm among nations defiant over claims to the South China Sea.

Well, here's an update from the region's most hotly disputed body of water.

Reuters reports today that Chinese vessels are sabotaging Vietnamese ships scouting for oil.

China, via its state media, is promising that it will speed up its already rapid development of contested territories.

And in a development that has serious potential to spark violent resistance, both Vietnam and China vow to stop, search and seize any foreign vessels plying disputed waters, according to the Wall Street Journal.

Obama's remarks on the contested waters hit all the right notes. But it's now safe to say that his pleas had almost no effect on the disputed sea's claimants.