An F-18 Hornet fighter jet with an AIM-174B long-range missile.

The deployment of new ultra-long-range air-to-air missiles by the US Navy in the Indo-Pacific could erase China’s air range advantage, experts say, and is part of an increasing focus on showcasing power amid high tensions in the region.
The AIM-174B, a development of the already available Raytheon SM-6 anti-aircraft missile, is the longest-range missile the United States has ever deployed and was officially recognized in July.
It has three main 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 like the AIM-174B, which can attack air targets up to 400 kilometers away, has a longer range than the Chinese PL-15 missiles. This allows US fighter jets to keep threats further away from aircraft carriers and safely attack “high-value” Chinese targets such as command and control aircraft.
“The United States can ensure the security of its key assets, such as carrier rocket groups, and launch long-range attacks on People’s Liberation Army targets,” said Chieh Chung, a researcher at the Taipei-based Association of Strategic Foresight think tank, using the acronym for the People’s Liberation Army.
The West has not yet succeeded in doing this easily.
The AIM-120, the standard long-range missile for US aircraft, has a maximum range of about 150 km, requiring launching aircraft to fly deeper into contested territory, putting aircraft carriers at greater risk of ship-to-ship attacks.
Any conflict in the South China Sea within the so-called First Island Chain, which stretches from Indonesia in the northeast to the Japanese mainland, would mean that the US Navy would operate within a radius of a few hundred kilometers of its Chinese opponent.
Supporting Taiwan in an invasion would require even greater naval involvement.
The AIM-174B changes that equation by keeping the People’s Liberation Army’s carrier-based fighters out of its firing range and even endangering its attack aircraft on Taiwan, Cheih said. This increases the likelihood that the United States will become involved in a larger conflict in the region, he added.
“The most important thing is that it allows the United States to move a little further into the South China Sea in the event of a conflict,” said a senior U.S. defense technical analyst who asked not to be identified because the matter is sensitive.
“And it will potentially change Chinese behavior because it will put large, slow and unmaneuverable aircraft at greater risk.”
Reach advantage
For decades, the US’s lead in stealth fighter aircraft – first with the F-117 and later with the F-22 and F-35 – was sufficient to make missiles like the AIM-120 completely sufficient.
The U.S. military also pushed for the development of AMRAAM as a cheaper alternative to a new missile and has dramatically improved its capabilities over the decades, says Justin Bronk, an air force and technology expert at the Royal United Services Institute in London.
According to the Missile Defense Advocacy Alliance, the cost of the SM-6 is estimated at around $4 million each, while the cost of an AMRAAM is around $1 million.
European countries, which until a few years ago did not have access to stealth technology, developed the Meteor missile, manufactured by MBDA, with a ramjet engine and a range of 200 km.
MBDA did not respond to a request for comment.
The introduction of Chinese stealth aircraft such as the J-20 and, more importantly, PL-15 missiles that can transport these aircraft domestically and have a range of 250 kilometers or more, have undermined the U.S. lead, says Kelly Grieco, a senior fellow at the Stimson Center.
Now a stealth Chinese aircraft could theoretically detect U.S. aircraft without stealth bombers and shoot them down well beyond the range at which they could possibly strike back, she said.
Even American stealth aircraft could be forced to fly dangerously close to fire their missiles.
“If a Chinese fighter jet can outfly an American fighter jet, that means it can fire the first shot,” she said. “It’s hard to outrun a plane traveling at Mach 4.”
The AIM-174B was developed to quickly meet this need.
The secret Lockheed Martin AIM-260, a separate U.S. Air Force program to develop an extremely long-range air-to-air missile small enough to be carried internally by stealth aircraft, has been in development for at least seven years.
Lockheed Martin declined to comment on the project.
China is currently developing missiles with a longer range than the PL-15, Bronk said, but the radar on the launching aircraft may not be able to detect targets at such distances.
“If you choose rockets that are too big and too heavy, you end up having to forego fuel,” he added.
Availability
By using Raytheon’s SM-6, originally developed for ship-based air defense, production lines are already available and funding has already been allocated to produce more than 100 SM-6 missiles per year.
Raytheon declined to say how many AIM-174Bs would be produced or whether existing SM-6s would be converted.
So far, it has only been shown on US Navy F/A-18E/F Super Hornet aircraft operated by the US and Australian military.
For the United States, Australia is an important ally and location for power projection in the South China Sea, which is why they are investing hundreds of millions of dollars in military infrastructure there.
The Australian Department of Defence said it was “working closely with the United States to understand the capability options for Australia to consider”.
The US Department of Defense referred questions about the AIM-174B to the US Navy.
The Navy said the missile was “operational” but declined to say whether it would be delivered to allies, whether it would be integrated into other aircraft or how many AIM-174Bs it plans to have annually.
The versatility of the SM-6, which has also been used to attack ships, land targets and missiles, opens up possibilities beyond the AIM-174B, said Peter Layton, a defense and aviation expert at the Griffith Asia Institute.
For example, if it were equipped with an anti-radar seeker, it could attack and disrupt surface-to-air missile batteries from extremely long ranges.
However, the addition of the AIM-174B to the US Navy’s arsenal – albeit not yet in large numbers – changes the forecast for a regional conflict for the time being, said the senior technical analyst.
“If that’s enough to push China’s high-end aircraft far back, then you don’t need many more,” the analyst added.
“Because the threat has caused the adversary to change its behavior … It makes a South China Sea scenario easier.” — Reuters