[Source: Reuters]

The U.S. 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 (RTX.N), opens a new tab SM-6 air defense missile, is the longest-range such missile the United States has ever fielded and was officially acknowledged in July.

It has three key advantages: it can fly several times farther than the next-best U.S. 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 400 km, outranges China’s PL-15 missile, allowing U.S. jets to keep threats farther from aircraft carriers, and safely strike “high-value” Chinese targets, such as command-and-control planes.

The West has not easily been able to do that until now.

The AIM-120, the standard long-range missile for U.S. aircraft, has a maximum range of about 150 km, 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 northeast to the Japanese mainland, means the U.S. Navy would operate within few hundred kilometers 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 United States would get involved in a major conflict in the region, he added.

For decades, the United States’ 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 U.S. military also leaned into 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 $4 million each, says the Missile Defense Advocacy Alliance, while an AMRAAM costs about $1 million.

European nations, which lacked access to stealth technology until recent years, developed the ramjet-powered Meteor missile, with a range of 200 km (124 miles), produced by MBDA.

MBDA did not respond to a request for comment.

The advent of Chinese stealth aircraft such as the J-20, and more important, the PL-15 missile it can carry internally – with a range of 250 km (155 miles) or more – eroded the U.S. edge, said Kelly Grieco, a senior fellow at the Stimson Center.

Now a stealthy Chinese aircraft could theoretically spot non-stealthy U.S. aircraft and shoot them down well outside the range where they could even fight back, she said.

Even U.S. stealth aircraft might be forced to fly dangerously close to fire their missiles.

The AIM-174B was developed to quickly address that need.

The secretive Lockheed Martin, opens new tab AIM-260, a separate U.S. Air Force program 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.

Lockheed Martin declined to comment on the project.

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.