Russia has been perhaps the most explicit in its desire to return to Cam Ranh Bay. Russian experts were hired for the recent modernization of the port, and Vietnam allowed the airfield to be used for refueling Russian bombers, prompting serious concern from the State Department. A base in Vietnam would be of largely symbolic value for Russia (the Russian Navy would be able to spare a handful of ships, at best) but it comports with the Kremlin’s broader strategy of restoring international prestige and playing a more active global role. Also working in its favor are longstanding military relations with Vietnam; the Vietnamese military continues to acquire most of its weaponry from Russia, including a recent $2.6 billion purchase of Kilo-class submarines. For its part, Vietnam has been publicly supportive of greater Russian involvement that falls short of outright ownership of the base: Hanoi recently granted Russia simplified naval access to the port.

http://nationalinterest.org/feature/vietnamese-base-will-decide-the-south-china-seas-fate-16093?page=2