WASHINGTON/BEIJING — The crux of the AUKUS defense pact announced Wednesday by the U.S., the U.K. and Australia is an arrangement that will give Canberra its first nuclear-powered submarines and boost the naval power of another American ally in the Pacific.
Underwater warfare has emerged as the next area of competition in the U.S.-China military rivalry, now that China is believed to have significantly reduced America’s dominance of the skies.
“Our nations will update and enhance our shared ability to take on the threats of the 21st century just as we did in the 20th century: together,” U.S. President Joe Biden said of the new framework at the White House on Wednesday.
Biden did not expand on what these threats were, but the comment was largely seen as a reference to China.
Only six nuclear powers — the U.S., the U.K., France, Russia, China and India — now possess nuclear submarines, which are more silent and can lurk underwater for longer than diesel-powered subs. Before Australia, the U.S. had provided the technology only to the U.K. back in 1958.
The U.S. has been developing nuclear submarines since the Cold War, and still maintains an edge over China when it comes to stealth, continuity of operations, and the ability to monitor and detect enemy vessels. Besides their solo missions, submarines help reinforce American control of the seas by providing an additional layer of protection for aircraft carriers and destroyers.
The historic decision to offer this know-how to Australia comes amid mounting U.S. concerns over the military balance in the Indo-Pacific.
The U.S. held an overwhelming air advantage over China in a potential military crisis over Taiwan as of 1996, according to a study by the Rand Corp.
But that gap has narrowed over the years, and Rand concludes the two countries reached approximate parity by 2017. China now holds over 1,250 surface-based missiles with a range of 500 to 5,500 km, the type of weapons that the U.S. was banned from deploying under the now-defunct Intermediate-range Nuclear Forces Treaty with Russia.
The U.S. possesses no missiles with this range.
China has two aircraft carriers, 56 submarines, 1,250 fighter jets and eight amphibious assault ships. Meanwhile, the U.S. forward deployment in the Indo-Pacific includes one aircraft carrier, 250 fighter jets and four amphibious assault ships.
China is now focusing on eliminating its last major maritime disadvantage against the U.S. in underwater warfare.
In April, Chinese President Xi Jinping attended a commissioning ceremony for three vessels at a naval port in Sanya. The highlight of the event was the Changzheng-18, a Type 094 nuclear-powered submarine.
The Changzheng-18 can be equipped with 12 JL-2 ballistic missiles, which have a maximum range of about 8,000 km and are capable of carrying nuclear warheads. Reported to be China’s most advanced nuclear submarine to date, it is designed to serve as a strategic deterrent against the U.S.
Of China’s 56 submarines, 10 are nuclear-powered, according to a U.S. Defense Department report. Its submarine fleet is expected to expand to between 65 and 70 vessels by the end of the decade.
The U.S. is said to deploy around 10 submarines across the entire Pacific region. Its ally Japan plans to have 22 submarines by the end of March, but even combined, the numbers do not match the Chinese fleet.
Meanwhile, China has become even more daring in its submarine activity. On Sept. 10, Japan detected a suspected Chinese submarine in the contiguous zone off the East China Sea island of Amami Oshima. The SDF in January 2018 also found a Chinese submarine in the contiguous zone around the Japan-controlled Senkaku Islands, which are claimed by China as the Diaoyu. The vessel promptly surfaced and showed its flag, signaling intentions of innocent passage.
China’s maritime activity has also expanded closer to Australia in recent years. Strategic choke points those waters include the Lombok Strait off the Indonesian island of Bali.
Supplying Australia with nuclear submarines would give Canberra a role in monitoring and deterring Chinese naval power in parts of the Pacific, and potentially help ease the U.S.’s numerical disadvantage against China’s submarine fleet.
Retired Adm. Philip Davidson, former commander of the U.S. Indo-Pacific Command, warned this year that China could attempt to take control of Taiwan by 2027. He stressed the importance of U.S. cooperation with its allies in a recent interview with Nikkei.
Chinese forces are closing the gap with U.S. and Japanese forces “with training, by establishing joint command and control structures, and by working the combat support logistics that’s necessary there,” he said.
“But at the moment, I think U.S. and Japanese forces are in the lead.”
Even as it tries to outgun the U.S., if not in quality then in quantity, China has slammed the U.S. decision to provide nuclear submarine technology to Australia.
“The nuclear submarine cooperation between the U.S., the U.K. and Australia has seriously undermined regional peace and stability, intensified the arms race and undermined international nonproliferation efforts,” Chinese Foreign Ministry spokesperson Zhao Lijian told reporters Thursday.