The underground base can reportedly hold up to 20 submarines, including new nuclear-armed submarines. It is also apparently big enough to hold future aircraft carrier groups if China decides to build them.
Military analysts say that the base is part of China's long-term plan to beef up its naval and nuclear might. They say the expansion is aimed at deterring Taiwan from making its de facto independence permanent, better protecting China's seaborne energy supplies, and projecting Chinese power far beyond its shores.
China is also replacing about 20 silo-based intercontinental ballistic missiles (ICBMs) capable of hitting the US with a new strategic force that includes road-mobile nuclear ICBMs and submarine-launched, nuclear-tipped ballistic missiles, which are less vulnerable to attack. Jane's Intelligence Review, the British-based defense periodical, reported that commercially available satellite imagery had confirmed China's construction of the new base near Sanya, on China's southern Hainan Island. Military sources knew about the planned base since 2002.
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.
China's foreign ministry refused to confirm or deny the report about the base, according to Reuters.
"China is going down the road of peaceful development. China's national defence policy is defensive. Other countries have no reason to fear, or make a fuss about it and be prickly," [Foreign Ministry spokesman Qin Gang] told a regular news conference.
Meanwhile, some US experts are calling for a strengthening of alliances in the region to counter the growing military challenge from China, reports Agence France-Presse. Arthur Waldron, of the University of Pennsylvania, said the US should strengthen alliances with Japan, South Korea, Taiwan, the Philippines, and Singapore to contain China's military strength.
James Lyons, an ex-commander of the US Pacific Fleet, said the US should use the same tactics it used to contain the Soviet Union during the cold war. One of Lyons's suggestions: increase US ties with the Philippines by leasing fighter jets and Navy vessels to the island nation.
The revelations about the base near Sanya come as the Pentagon is seeking to forge better ties with its military counterparts in China. The Christian Science Monitor reported earlier this year that US-China military relations still lag behind the two countries' diplomatic and economic relations. The Pentagon hopes that better communication can help clarify the intent behind China's rapid military buildup.
The new base is also raising concerns in India, reports the Asia Times from New Delhi. It said Indian defense experts view China as a long-term military threat, since the two countries have overlapping interests in the Indian Ocean. India recently tested its own Agni III ballistic missile, that will be capable of hitting Beijing and Shanghai.
Indian Express reports that the new Jin-class submarine deployed at the base carries 12 nuclear-tipped ballistic missiles. It notes that the new base in Hainan is 1,200 nautical miles from the Malacca Strait, through which some of China's energy supplies pass from the Indian Ocean.
The new base could help provide China with the ability to cut off commercial traffic through the strait in a crisis. It said China's new base could also spur India to accelerate its own nuclear submarine program. Sea trials for the first sub are set for next year.
The Times of India reports that the extent of the new Chinese base has "jolted the Indian defence establishment." India has nuclear weapons, too, but has yet to develop its own nuclear-armed submarines, a deficiency that "has long troubled defence planners."
While an adversary can take out missile silos and airbases in pre-emptive strikes, it's difficult to target nuclear submarines which can remain underwater for prolonged periods.
The sheer importance of the underwater nuclear deterrent can be gauged from the fact that even the US and Russia will ensure that two-thirds of the strategic warheads they eventually retain, under arms reduction agreements, will be in the shape of SLBMs [submarine-launched ballistic missiles].
Writing in the Federation of American Scientists' Strategic Security Blog, Hans Kristensen strikes a skeptical note. He says that the Chinese have very little experience in operating ballistic missile submarines, so it's not clear yet how strategically significant the new base will be. He suggested that the US could easily monitor Chinese movements from the base, which is near deep water.
The U.S. navy has several decades of experience in trailing Soviet SSBNs [nuclear-powered submarines armed with ballistic nuclear missiles] in the open oceans; shallow waters are much more challenging. And the South China Sea is a busy area for U.S. attack submarines, which have unconstrained access to the waters off Hainan Island. And I'd be surprised if there were not a U.S. "shadow" following the Jin-class SSBN when it arrived at Hainan Island.
Bates Gill, head of the Stockholm International Peace Research Institute (Sipri), said that [China] was developing more flexible delivery systems, including from submarines, as well as the capacity to use multiple warheads.
"Among the major nuclear powers China stands out in its effort to modernise, expand and improve its nuclear weapons capability," he said in Beijing today.
"We see some very interesting and quite dramatic changes in the way its nuclear deterrent operates."