China might come under pressure to reconsider its long-standing "no first use" nuclear policy as it engages in a maritime arms race with the United States, analysts have warned.
Nuclear competition is brewing between the two countries as China makes gains in weapons development and Washington tries to limit Beijing's military build-up in the South China Sea.
The United States is still decades ahead in nuclear weapons development but a successful test late last year of China's new submarine-launched ballistic missile, the JL-3, is cause for concern in Washington.
The test signals that China is moving ahead with a new class of strategic submarines called SSBNs, vessels that could be equipped with nuclear-armed JL-3s and that would be more difficult to detect than conventional land-based nuclear weapons.
In a sign of that growing concern, U.S. President Donald Trump said in October that his decision to withdraw from a decades-old atomic accord with Russia was driven by a need to respond to China's nuclear build-up.
U.S. Vice President Mike Pence has also stressed that the U.S. Navy would "continue to fly, sail and operate wherever international law allowed" in the South China Sea ― remarks that Beijing took as aimed at China.
According to Zhao Tong, a fellow in Carnegie's Nuclear Policy Program, based at the Carnegie―Tsinghua Centre for Global Policy, the U.S. and its allies are stepping up their anti-submarine warfare in the South China Sea and the Indian Ocean.
In a report late last year, Zhao said this was increasing mistrust between the two countries and raising the possibility that Beijing might rethink the "no first use" nuclear weapons policy, which has been in place since the first Chinese nuclear test in 1964.
In a separate report, the Washington-based U.S.-China Economic and Security Review Commission said Beijing was looking at expanding its nuclear delivery systems, setting off debate in China over whether its nuclear arms should be used only as a deterrent and not as a "first strike".
The United States and China are both capable of delivering nuclear weapons through three systems: land-launched nuclear missiles, nuclear missile-armed submarines and strategic aircraft with nuclear bombs and missiles.
The JL, or Julang, series of missiles for nuclear-powered submarines is part of a People's Liberation Army strategy to extend the country's nuclear retaliation capabilities further from land to sea.
But China trails the U.S. in these areas by decades, a technological gap that means Beijing could only for now work on its capacity to retaliate, or "second strike" options.
One military source said that unlike the U.S., China was incapable of launching a pre-emptive strike and so had little choice but to retain its "no first use" policy.
Hong Kong-based military expert Song Zhongping said China's nuclear capability was also well behind that of Russia. The U.S. and Russia combined have more than 90 per cent of the world's nuclear weapons.
"China needs to strengthen and improve its at-sea nuclear deterrent capability by increasing both the quality and quantity of its SSBNs and attack subs because the U.S. is making every effort to restrain Chinese strategic subs from sailing further," Song said.
He said America's moves "are aimed at undermining Beijing's second-strike capability", adding that Beijing's decision to develop more nuclear subs "was also pushed by the massive replacement of old generation [submarine-launched ballistic missiles]".
Observers said the Chinese navy's successful flight test of the JL-3 missile in the Yellow Sea in late November had encouraged the PLA Navy to press on with developing the new generation of strategic submarines known as the Type 096.
The JL-3 is designed to be carried and launched by the Type 096, which are attack submarines that are more difficult to detect than land-based missile launchers and can move furtively near enemy waters.
The missile is based on the PLA Rocket Force's land-based DF-41 intercontinental ballistic missile, which has a flight range of 12,000 kilometers (7,456 miles) and could potentially hit any U.S. mainland target within an hour.
And while the new missile has flight range of about 9,000km (5,600 miles), Chinese military experts say it could be extended to 12,000 kilometers when fully developed, putting it on a par with U.S. and Russian equivalents.
And there appears to be the political will to develop the technology.
A retired naval official said the Central Military Commission, which is chaired by President Xi Jinping and oversees the military, had set aside an enormous sum of money for upgrading and replacing China's naval weapons, particularly its SSBN fleet.
"Funding is not a problem ― the navy has so much money to burn," the former warship commander said, speaking on condition of anonymity.
The commander said China hoped to narrow its technology gap with the U.S. in SSBNs from 30 years to about 10 years by 2025, when both the next generation of these subs and of submarine-launched ballistic missiles would join the navy.
The nuclear-powered ballistic missile submarines and aircraft carriers were the "two most powerful and cutting-edge strategic weapons that China should pull out all the stops to develop", the commander said, adding that construction of the Type 096 is already under way.
The PLA Navy so far has four Type 094 nuclear-powered ballistic missile submarines, each outfitted with 16 JL-2 missiles for routine underwater patrols ― equivalent to the missile component of their Western counterparts. But military experts said China's four Type 094 subs would not adequately safeguard the country's national security.
Meanwhile, the U.S. Navy has 18 Ohio-class nuclear-powered submarines, with 14 capable of carrying up to 24 powerful Trident I missiles. But America also is developing its next-generation Columbia-class submarines, which will carry 16 of its most advanced Trident II missiles.
Antony Wong Dong, a Macau-based military observer, said the shortcomings and limited number of China's sea-based nuclear weapons had constrained China's military capability during peacetime patrols.
"The JL-2 is a single-warhead missile, while the Type 094 is well-known for its noise and is easy to detect," Wong said. "That's why China needs to develop the JL-3, which is expected to carry multiple warheads with a longer range."
Song said China's aircraft carrier projects would accelerate its nuclear submarine build-up since subs were needed to provide underwater protection for the flotillas.
China plans to build at least four carrier battle groups by 2035 to achieve its goal of having a maritime force capable of operating across the deep waters of open oceans and defending the country's expanding overseas interests. In the past year, it has launched two aircraft carriers and started construction on its new-generation aircraft carrier, the Type 002.
Collin Koh, a research fellow at the S. Rajaratnam School of International Studies at Nanyang Technological University in Singapore, said China might be trying to boost its sea-based deterrent capability strength by developing an array of weapons to enhance its offensive strike capacity.
But Beijing's effort to develop precise land-based launchers, solid-fueled ICBMs and hypersonic gliders would escalate the arms race among Beijing, Washington and other countries in the region, he warned.
"In various regional conflict scenarios we might have to take into account not just the role of the U.S. Navy in tackling the Chinese SSBN threat but also the prospective roles played by other U.S. allies and partners," he said.
Several U.S. partners "have built up significant [anti-submarine warfare] capabilities across the region", he said. (SCMP)