Hypersonic missiles are not a terrifying new weapon. They are just another cog in the terrifying but remarkably stable strategy called nuclear deterrence. “The Avangard hypersonic glide vehicle entered service at 10:00 Moscow time on 27 December,” boasted Russian Defense Minister Sergei Shoigu — and nobody quailed in their boots.

The new Russian missile can deliver nuclear weapons, of course, and the Russians are very proud of it. As President Vladimir Putin said, “Not a single (other) country possesses hypersonic weapons, let alone continental-range hypersonic weapons.”

A hypersonic missile’s warheads launch on a rocket. However, instead of going very high and traveling most of the distance through space in a predictable ballistic trajectory before plunging back down into the atmosphere and striking their target, the hypersonic missile’s warheads go low early.

The hypersonic missile launches on a depressed trajectory, and then a glide vehicle detaches from the rocket and skips along the edge of the atmosphere, traveling at up to 20 times the speed of sound. It only comes over the horizon and becomes visible to the enemy’s missile defense radars when it’s much closer to the target.

Even better, it can maneuver on the way in to its target, which makes it harder to intercept. This would be deeply alarming to Russia’s potential adversaries if all the orthodox, traditional ICBM had suddenly become vulnerable to interception. Then only the Russians would have missiles that could get through the other side’s defences, and so they would rule the world. But in fact there are no effective defenses against mass attacks by conventional ICBMs.

The United States has been working on anti-ballistic missile (ABM) systems for almost four decades and it does have one active ABM site in Alaska. It might be able to stop one or two incoming ICBMs launched by, let’s say, North Korea. It certainly couldn’t stop the hundreds of ICBMs that Russia would launch in any real nuclear war.

The problem with any kind of anti-missile defense system is that it’s relatively cheap and easy to overwhelm it by sheer numbers. The dumb old ICBMs will still get through any ABM defenses if used in quantity, which is how they would certainly be used in any great-power war. Hypersonic missiles are wonderfully fast and clever, but they’re also expensive and quite unnecessary.

So why has Russia spent what is clearly a great deal of money to develop a snazzy but pointless weapon? Because the Russian military-industrial complex is still alive and kicking despite the demise of the old Soviet Union. Developing new weapons is what it does, whether they are needed or not.

This provides an entire Russian industry with interesting and well-paid jobs. In return, the industry provides the regime with cool new weapons that make it look powerful and even fearsome to people who don’t understand nuclear deterrence. These cool new weapons don’t actually change the strategic realities, but who cares? Nobody’s really planning to use them anyway.

That is not to say that nuclear weapons are not dangerous. Of course they are, and although nuclear deterrence has kept nuclear war at bay for three-quarters of a century, there is no guarantee that it will work forever. We would be much safer if these weapons were abolished.

But the long strategic stalemate will not be destabilized by some flashy new gadget like hypersonic missiles. As long as no effective defense is available against mass attacks with nuclear-armed missiles, mutual deterrence will persist. The only technological development that could really undermine it is directed-energy weapons.

High-energy lasers and particle-beam weapons would be far more effective than the ground-launched missiles employed in today’s ABM systems. They would function at light speed, they would have absolutely flat trajectories (which allows precise targeting) and they would be able to switch almost instantaneously from one target to the next.

In theory, therefore, directed-energy weapons would make effective defense possible against any nuclear attack using missiles, whether they are ICBMs, cruise missiles or hypersonic gliders. In practice, however, nobody has come up with an operationally credible directed-energy weapon.

Maybe one day they will, but until then innovations like hypersonic missiles are just minor new wrinkles in an essentially unchanging strategic scene. Both the Americans and the Chinese have been experimenting with the same hypersonic technologies, but neither is in any rush to deploy them.

Gwynne Dyer is an independent journalist.