During a recent visit to Vietnam, Russia President Vladimir Putin told media that Russia and Vietnam were discussing the establishment of a material and technical support station in Cam Ranh Bay. In recent years, military cooperation between Russia and Vietnam has been increasing, driven by the strategic concerns of both sides.

Cam Ranh Bay was one of the most important overseas bases of the Soviet Union during the Cold War. It never faded far away from Russia's strategic vision, but Russia eventually mothballed the base due to economic constraints.

One of the reasons for Russia to return to Cam Ranh Bay is to display its ambition. Russia's current leadership sees the country's renaissance as its main goal, sticking to a tough line both in strategy and diplomacy. Besides, Russia is attempting to expand its strategic room for movement.

Returning to Cam Ranh Bay is one of the important strategic steps Russia can take to gain a foothold in the Pacific region once again.

It is predictable that Russia will keep its tough stance on the Southern Kuril Islands, known by Japan as the Northern Territories. Thus, it would ensure the security of its channels to the Pacific in the north, while expanding southward to Cam Ranh Bay, and in so doing recreate the sphere of influence the Soviet Union once had in Southeast Asia.

For Vietnam, in order to maintain and expand its vested interests in the South China Sea, it has been instigating external forces to interfere there. Vietnam has strengthened military ties with the US, Japan, India and Russia. Since last year, with military relations between Vietnam and the US drawing closer, Vietnam revealed its plan to rent out Cam Ranh Bay. It even invited US Defense Secretary Leon Panetta to visit the bay. However, Vietnam knows well that cooperating with the US is risky. It wants to avoid overly stimulating China while seeking strong external support, so Russia is the best choice.

Russia's return to Cam Ranh Bay will increase the complexity of the South China Sea issue. No matter whether military cooperations bring the Philippines and the US closer or sketch new ties between Russia and Vietnam, both add to the cost for China to maintain its interests in the South China Sea.

However, Russia's return could also bring opportunities. Russia and the US both in the Southeast Asia again could create more strategic room for China. There have already been various external forces acting in the Southeast Asia. Russia's return may not only bring threats but also provide more diplomatic maneuvering room for China.

The author is researcher of the Chinese Naval Research Institute. opinion@globaltimes.com.cn