Tensions are rising again in the South China Sea with reports that China has deployed surface to air missiles on the disputed Paracel Islands, which are also claimed by Vietnam.
Vietnam is also strengthening its posture in the region, taking delivery of a fifth Kilo-class submarine. It has also announced closer cooperation with India.
The report, citing satellite evidence, that China has stationed a new missile system on a disputed outpost drew an immediate reaction from the United States.
“There is every evidence, every day that there has been an increase of militarisation of one kind or another,” the Secretary of State, John Kerry, told reporters. “It’s of serious concern…we have had these conversations with the Chinese, and I am confident that over the next days we will have further very serious conversation on this,” he said.
In a move, tacitly welcomed by Vietnam, the US has continued to assert its naval power in the region in a clear challenge to China’s growing military presence.
At the end of last month, the US sailed a destroyer within 12 miles of a Chinese occupied island in the Paracels.
The US navy uses facilities in Singapore and Malaysia for its operations, and can count on open support from Vietnam and the Philippines as it seeks to assert “freedom of navigation” in the South China Sea.
Other ASEAN countries, however, have resisted an open challenge to Beijing’s growing ambitions in a vast expanse of ocean, that stretches from the waters off Borneo to the Vietnamese coast and the northern Philippines.
Vietnam is looking for allies further afield, opening the deep water port facilities at Cam Ranh Bay to visits by Indian and Japanese warships – two countries looking to weigh the balance against what they see as a growing threat from Beijing.
In recent days, Vietnam has announced an agreement with India to open a satellite tracking station in Ho Chi Minh City – a move with civilian applications but which will also help it monitor Chinese movements in the disputed waters.
Vietnam has also sought cooperation on drone technology, most notably with Belarus, in another step to boost its intelligence and reconnaissance capabilities.
China responded with indignation to the latest intervention by a US warship near one of its bases in the Paracels.
The foreign ministry in Beijing also put out a statement in response to reports that the US and India have discussed mounting joint naval patrols in the Indian Ocean and the South China Sea.
“Countries from outside the area must stop pushing forward the militarisation of the South China Sea, cease endangering the sovereignty and national security of littoral countries in the name of ‘freedom of navigation’ and harming the peace and stability of the region,” said a spokesperson in response to questions from the Reuters news agency.
Other new satellite evidence shows that China is currently conducting dredging and reclamation work at two sites in the Paracels. Analysts said the aim appeared to be the construction of helicopter bases which would help counter any threat from submarines.
Beijing last year built three new airfields on artificial islands built on reefs in the Spratly Islands and has since flown in what it calls “civilian flights” on test runs to the platforms.
The Vietnamese prime minister, Nguyen Tan Dung, directly called for a stronger US presence in the South China Sea during this week’s summit between ASEAN leaders and President Obama at the Sunnylands Centre in California.
He may be a spent force in Vietnamese politics following the recent party congress, but the newly reappointed Communist party leader, Nguyen Phu Trong, has also shown that he can stand up to Beijing.
Mr Trong surprised many with the boldness of his visit to the White House in July and his words of friendship towards the United States.
Despite the political tussles in Vietnam in recent months, and the victory of conservatives within the party, there is no sign of an imminent reconciliation with China.
An ever more dangerous tussle over disputed reefs, islets and shoals, whose strategic importance is out of all proportion to their size and usefulness, looks set to continue.