The intrigue in the US-China-Vietnam triangular relationship deepened on Aug 13, when General Martin Dempsey, chairman of the Joint Chiefs of Staff of the United States Armed Forces, visited Vietnam and met top military and political leaders. No doubt, China will watch with weary eyes, and perhaps even lament that this romance between its competitors is all its own doing.
Gen Dempsey, sent by Defence Secretary Chuck Hagel, said Mr Hagel and President Barack Obama told him: "The place for you right now is Vietnam."
His visit is the first by a top military commander from the US since 1971. And it was made despite other urgent military situations in the Middle East and eastern Europe.
The historic visit followed the return of US Senator John McCain from a trip to Hanoi a week earlier, and the visit of Vietnamese Political Bureau member Pham Quang Nghi to the US late last month.
After the talks, Gen Dempsey and Vietnamese leaders were quoted as saying that they had discussed regional security issues, military cooperation, resolving issues related to the use of the Agent Orange defoliant by the US during the Vietnam War, Vietnamese participation in United Nations peacekeeping forces and the sale of weapons to Vietnam.
However, the significance of the visit lies in the way it marks a new era in US-Vietnam relationships. If Vietnam gets what it wants in terms of the issues listed above, Hanoi could begin to pivot clearly towards the US. Mr McCain, a Republican, was accompanied by Democratic Senator Sheldon Whitehouse on his visit. He indicated that support is gradually growing for arms sales to Vietnam.
Among those he met in Hanoi was Mr Nguyen Phu Trong, general secretary of the Communist Party of Vietnam. In his talk with Vietnamese Defence Minister Phung Quang Thanh, Mr McCain was said to have discussed cooperation with Vietnam in maritime security and navigation safety. These matters are of great concern to the US and no doubt are also of great interest to the Vietnamese in their territorial disputes with China. Gen Dempsey met Vietnamese Prime Minister Nguyen Tan Dung as well.
The message that emerged from these meetings was a strong commitment on both sides to a deeper and more comprehensive relationship.
According to non-official sources, the US is also supposed to have reassured Vietnam's Communist Party that Washington would not seek a change of regime, although it would continue to place emphasis on the need for the human rights situation to improve.
Pundits are predicting the release of activists who have publicly called on Vietnam to pivot away from China and towards the West.
This dramatic turn of events and the quick succession of visits would have been impossible if not for the recent confrontations in the South China Sea between China and Vietnam. China's unilateral declaration of a new Air Defence Identification Zone over the sea neighbouring Japan would also have riled both its North-east Asian neighbours and the US, a military ally of South Korea and Japan.
Even so, conversations with military and top party officials reveal that though a closer relationship with the US could be advantageous for Hanoi, some party members, as well as Vietnamese leaders who fought in the war with the US, might not like it.
China can be expected to use its lobbying power within Vietnam to present opposing views. It is also quite possible that Hanoi is simply posturing, in an attempt to get China to treat Vietnam more favourably.
Moreover, there is a substantial lobby within Congress, as well as among Vietnamese Americans, that wants communist Vietnam to liberalise its domestic politics and society before relations can be improved.
And these initiatives are seen mainly as part of Mr Obama's foreign policy - it is uncertain whether the next US president would give them the same priority.
Still, China will be concerned about whether the improved military relationship might impede its ability to flex its military muscles. If the US is able to establish a military presence in Vietnam, then US forces in Vietnam, Okinawa and the Philippines would form an interdicting chain across the South China Sea, which would prevent Chinese military forces from acting at will.
China might seek to pre-empt such a possibility by being more forthcoming in discussions with Vietnam to resolve territorial disputes, and move more quickly than before on the Code of Conduct with Asean, which has been delayed for years.
How Vietnam chooses to act in the face of such Chinese carrots will reflect the extent of its commitment to Asean.
Unfortunately for China, Beijing's assertiveness towards neighbours with which it has disputes has been a public relations disaster.
Image-wise, China has turned from a peaceful, rising giant into a powerful bully, seeking to change an existing international order based on peace and equality into one that sees China gaining premier status.
The writer is an independent consultant who has studied Vietnam for 20 years.