Moscow has long stated its desire for an agreement with Hanoi for a naval base on Vietnam's south-eastern coast at Cam Ranh Bay. Strategically placed, the port is one of the best deep-water ports on the South China Sea.

In late February, Russian Defence Minister Sergei Shoigu again noted — somewhat provocatively — Moscow's desire to expand its permanent military presence outside its borders, including in Vietnam.

Moscow is supporting the upgrade of facilities in Cam Ranh Bay and will create a maintenance facility for Russian ships there. But a permanent presence by way of a naval base (as the USSR had in Cam Ranh Bay for 23 years until 2002; pictured is a 1985 Pentagon depiction of the base) remains elusive.

Russian investment in Vietnam has long been significant and Moscow is Vietnam's main supplier of military hardware. In recent years, this has included orders for six Kilo-class submarines, a dozen SU-30MK2s fighter jets and six Gepard-class light frigates – the most recent order for the frigates was placed last month.

In 2001 a strategic partnership was signed between the two countries, and Prime Minister Medvedev visited in 2012 followed by President Putin late last year, during which a new wave of cooperation agreements were signed. Moscow is also courting Vietnam to enter into its Customs Union

As such, Russia's assertive stance in Crimea to protect its interests – notably its large naval facility – is being watched by Hanoi. Would Russia be similarly assertive in supporting Vietnam if it were to allow Moscow a permanent naval presence in Cam Ranh Bay?

There is some resistance from within Vietnam (which is recalibrating its foreign policy) and caution from other states that worry just what a stronger Russian presence in the South China Sea would mean.

Yet the average Vietnamese will also remember their country's 1974 naval defeat to China over the Paracel Islands. Indeed, at a domestic level there is continued suspicion of China. If China does become more assertive in the South China Sea, this could apply pressure on Hanoi to develop a counterweight to Beijing's influence. A Russian fleet in Cam Ranh Bay may just provide one.

Image courtesy of Wikipedia