THE United States navy's deployment of new extremely long-range air-to-air missiles in the Indo-Pacific could erase China's advantage in aerial reach, experts say, part of an intensifying focus on projecting power amid high tensions in the region.
The AIM-174B, developed from the readily available Raytheon SM-6 air defence missile, is the longest-range such missile the US has ever fielded and was officially acknowledged in July.
It has three advantages: it can fly several times farther than the next-best US option, the AIM-120 AMRAAM; it does not require new production lines; and it is compatible with the aircraft of at least one ally, Australia.
Crucially, a weapon such as the AIM-174B, which can attack aerial targets as far away as 400km, outranges China's PL-15 missile, allowing US jets to keep threats farther from aircraft carriers, and safely strike "high-value" Chinese targets, such as command-and-control planes.
"The United States can ensure the safety of their important assets, such as carrier groups, and launch long-range strikes on PLA targets," said Chieh Chung, a researcher at a Taipei-based thinktank, the Association of Strategic Foresight, using an abbreviation for the People's Liberation
Army.
The west has not easily been able to do that until now.
The AIM-120, the standard long-range missile for US aircraft, has a maximum range of about 150km, which requires the launching aircraft to fly deeper into contested territory, exposing aircraft carriers to greater danger of anti-ship attacks.
Any type of South China Sea conflict, within the so-called First Island Chain, which runs roughly from Indonesia's northeast to the Japanese mainland, means the US navy would operate within few hundred kilometres of its Chinese adversary.
Supporting Taiwan in an invasion would pull the navy in even closer.
The AIM-174B changes that equation, keeping PLA carrier-hunting aircraft out of firing range and even endangering their planes attacking Taiwan, Cheih said.
That increased the likelihood the US would get involved in a major conflict in the region, he added. "The big thing is that it lets the US push in a little bit further" into the South China Sea during a conflict, said a senior US defence technical analyst, who declined to be identified.
"And it's going to potentially change Chinese behaviour because it's going to hold large, slow, unmanoeuvrable aircraft at greater risk."
For decades, the US' advantage in stealth fighters, first with the F-117 and then with the F-22 and F-35, meant that missiles such as the AIM-120 were all that was needed.
The US military also leaned towards developing the AMRAAM as a cheaper alternative to a new missile, drastically improving its performance over decades, said Justin Bronk, an airpower and technology expert at London's Royal United Services Institute.
The SM-6 is estimated to cost about US$4 million each, says the Missile Defence Advocacy Alliance, while an AMRAAM costs about US$1 million.
European nations, which lacked access to stealth technology until recent years, developed the ramjet-powered Meteor missile, with a range of 200km, produced by MBDA.
The advent of Chinese stealth aircraft, such as the J-20, and more importantly, the PL-15 missile it can carry internally — with a range of 250km or more — eroded the US edge, said Kelly Grieco, a senior fellow at the Stimson Center, the US.
Now a stealthy Chinese aircraft could theoretically spot non-stealthy US aircraft and shoot them down well outside the range where they could even fight back, she said.
Even US stealth aircraft might be forced to fly dangerously close to fire their missiles.
"If a Chinese fighter can outrange an American fighter, it means they can get the first shot.
"It's hard to outrun something that's travelling at Mach 4."
The AIM-174B was developed to quickly address that need.
The secretive Lockheed Martin AIM-260, a separate US Air Force programme to develop an extremely long-range air-to-air missile small enough for stealth aircraft to carry internally, has been in development for at least seven years.
China is developing missiles with longer range than the PL-15, Bronk said, but the radar of launching aircraft may be unable to spot targets at such distances.
The writer is from Reuters