Vietnam is acquiring an impressive list of nuclear armed allies. Russia is now a major supplier of weapons to Vietnam, and is discussing returning to Cam Rahn Bay. France has been approached to supply high tech equipment and training for Vietnamese ground forces.
And India is on call (from the same Strategypage post):
Vietnam, seeking allies against possible Chinese aggression, has signed a series of military accords with India. Vietnam has already sent ship building personnel to India for training, and now India will send technical experts to Vietnam to help the Vietnamese navy develop more effective methods for repairing their warships. Indians have been repairing modern warships for over a century, first as employees of British ship repair operations, and then for Indian ones when the British left in 1947. India will also help teach Vietnamese military personnel English. Indian and Vietnamese troops will work together in mountain and jungle warfare exercises. India hopes to sell weapons to Vietnam as well.
All this will help Vietnam absorb some of China's military might away from India.
It will also help India project power into the South China Sea, since India will have access to Vietnamese ports:
In a significant gesture, Vietnam has offered repair and maintenance facilities for Indian warships at its ports, taking bilateral military relations up several notches. After a meeting with Defence Minister A K Antony in Hanoi, his counterpart Gen Phung Quang Thanh welcomed more port calls by the Indian Navy and offered maintenance and repair facilities for warships at Vietnam ports.
This would extend a major advantage to the Indian Navy that has been scaling up operations in the region, specially in the South China Sea where several patrols have been carried out in the past few years. Vietnam is strategically located in the region and has several sea ports, including Hai Phong, located near China's Hainan island, that could be of great interest to India.
I mentioned this concept before, although I thought Taiwan might be a logical source of this role as well:
In the longer run, it would be useful to India to have Vietnam and Taiwan as allies in case India needs to hit China's naval facilities on Hainan Island.
Perhaps that is a little too overt at this time. But it makes sense.
