China's protests against international oil firms signing exploration deals with Vietnam in the disputed South China Sea were more extensive - and successful - than previously thought, according to leaked US diplomatic cables released by WikiLeaks.
The cables highlight a campaign going back to 2006 that saw oil giants - including Exxon Mobil, BP and Chevron - as well as smaller firms such as Petronas of Malaysia, coming under pressure after striking deals with Hanoi. Some pulled out or put their exploration plans off southern Vietnam on ice.
By July 2007 a confidential cable from the US embassy in Hanoi noted that four US and eight foreign companies were involved, with about five deals suspended or cancelled.
The leaks come amid increasing concerns in Beijing, with Chinese ships cutting cables on a Hanoi-chartered survey vessel working for foreign firms in May. Officials also issued fresh warnings last week to India's state-owned oil giant against expanding oil and gas exploration with Vietnam.
'India should bear in mind that its actions in the South China Sea will push China to the limit. China cherishes the Sino-Indian friendship, but this does not mean China values it above all else,' an editorial in the state-run Global Times warned.
'China has been peaceful for so long that some countries doubt whether it will stick to its stated bottom line. China should remind them of how clear this line really is,' it said.