ANSWER: Vietnam plans to have a submarine brigade operational by 2017.
The Varshavyanka-class submarines are designed for anti-submarine warfare, anti- shipping and anti-surface ship warfare, patrol and general reconnaissance, and for the defence of naval bases and coastlines. They are capable of operating in relatively shallow water.
The assessment of whether or not Vietnam can absorb submarines and create a credible deterrent is now becoming clearer with reports by diplomatic observers that Vietnam’s submarines are undertaking patrols along Vietnam’s coast. More recent press accounts indicate that the Vietnamese submarines have commenced patrols without their Russian advisers. In addition, Vietnamese crews are currently undergoing training at India’s INS Satavahana submarine center in undersea warfare doctrine and tactics.
In 2017, when all six submarines are operational, they will add a major capability in Vietnam's ability to develop anti-access/area denial capabilities against any country seeking to enter Vietnamese waters with hostile intent. In addition, the Varshavyanka-class submarines will add a potent strike capability with their anti-ship and land attack cruise missiles.
Vietnam’s emerging submarine fleet will be based at Cam Ranh Bay. The ability of these submarines to deploy stealthily will be put at risk if China permanently stations anti-submarine warfare aircraft on Fiery Cross Reef where a three-kilometer long run-way has been constructed.
When all of Vietnam’s current and future arms acquisitions are taken into account it is evident that Vietnam has taken major steps to develop a robust capacity to resist maritime intervention by a hostile power. This has taken the form of developing a counter-intervention strategy that integrates shore-based artillery and missile systems; Su-30 multirole jet fighters; fast attack craft, corvettes and frigates armed with ship-to-ship missiles; and Varshavyanka-class submarines. These weapon systems should enable Vietnam to make it extremely costly for China to conduct maritime operations within a 200-300 nautical miles band of water along Vietnam’s coast from the Vietnam-China border in the northeast to around Da Nang in central Vietnam if not further south. Additionally, Vietnam also has the capacity to strike China’s major naval base near Sanya on Hainan Island and military facilities on Woody Island.