The Pentagon has announced its intentions to accelerate the development of America’s latest nuclear-armed air-launched cruise missile, the Long-Range Stand-Off (LRSO). Designed to replace the now aging AGM-86, the new missiles will be bomber-launched from a safer distance, ensuring the safety and survivability of airborne nuclear strikes.

A key part of the US’s “Nuclear Triad,” the LRSO will modernize and strengthen the airborne part of the package. This is important as this is arguably the most flexible part of The Triad, as bombers are more visible and can be recalled.

This move, according to reports, has been inspired by the development of ever-more advanced air defenses from nations like China and Russia. Systems like the S-400 and HQ-9 are key examples.

These systems detect aircraft at long range and can shoot down incoming missiles, and can work together in layered networks (radars, missiles, aircraft). Put together, this makes it much harder for bombers or older missile systems to survive and hit their targets.

Nuclear deterrence for the modern world

The key to this is something called “stand off,” as the name of the new system hints at. This is military jargon for firing something from far enough away so you don’t get shot down.

So instead of putting the aircraft in danger, bombers can stay hundreds or even thousands of km away to launch missiles from safety. The attack then only lets the missile do the risky part (i.e., entering enemy airspace).

To make this possible, the new LRSO is designed to be harder to detect using stealthy shapes and materials. This gives it a much smaller radar signature than older missiles, like the AGM-86.

The missiles will also have smarter navigation through using various sources, not just relying on global positioning systems (GPS). Such capability should make them very resilient to electronic warfare (EW) like jamming and spoofing.

The LRSO will also be able to fly low and “sneaky,” enabling it to follow terrain like hills and valleys autonomously. This should enable such a missile to “stay under the radar” for as long as possible before its final approach.

In combat, these missiles would be carried and launched by US bombers like the B-52 “Stratofortress” and B-21 “Raider.” The former will be able to carry large payloads of the LRSO, which could be launched en masse to overwhelm enemy defenses.

Fire and not forget

The B-21, on the other hand, is the US’s latest stealth bomber and, once operational, will be able to add its own stealth capabilities during missile deployments.

During a strike, multiple bombers would launch missiles from different directions at long distances. With multiple missiles launched (some being dummies), enemy air defenses would be overwhelmed, with some even evading detection.

Importantly, nuclear-armed weapons like the LRSO are more controllable and slower than another part of The Triad, Intercontinental Ballistic Missiles (ICBMs). Critically, LRSO, unlike ICBMs, can be redirected or even aborted mid-flight, something not possible with the latter.

That makes them useful for deterrence and escalation control, not just destruction.