China is constructing a major underground nuclear submarine base near Sanya, on Hainan Island off its southern coast, Jane's can confirm. Although Asian military sources have disclosed this fact to Jane's since 2002, high-resolution commercially available satellite imagery from DigitalGlobe allows independent verification of the previous suggestions.
The extent of construction indicates the Sanya base (also known as Yulin) could become a key future base for People's Liberation Army Navy (PLAN) aircraft carriers and other power-projection ships. In December 2007, perhaps in concert with a major PLAN exercise the previous month, the PLA moved its first Type 094 second-generation nuclear ballistic missile submarine (SSBN) to Sanya.
An underground submarine base and the positioning of China's most advanced sub-surface combatants at Sanya would have implications for China's control of the South China Sea and the strategically vital straits in the area. Further satellite imagery suggests the construction of Sanya has been supported by a gradual military build-up in the Paracel Islands over the last 20 years, and the transformation of the Chinese-occupied features in the Spratly Island group into assets that could support a range of military operations.
China's nuclear and naval build-up at Sanya underlines Beijing's desire to assert tighter control over this region. China's increasing dependence on imported petroleum and mineral resources has contributed to an intensified Chinese concern about defending its access to vital sea lanes, particularly to its south. It is this concern that in large part is driving China's development of power-projection naval forces such as aircraft carriers and long-range nuclear submarines.
China has pursued this build-up at Sanya with little fanfare, offering no public explanations regarding its plan to base nuclear weapons or advanced naval platforms there.
For both regional and extra-regional powers, it will be difficult to ignore that China is now building a major naval base at Sanya and may be preparing to house and protect a large proportion of its nuclear forces here, and even operate them from this base. This development so close to the Southeast Asian sea lanes so vital to the economies of Asia can only cause concern far beyond these straits.