Everyone is in an uproar about hypersonic weapons. The US and Japan are now expected to announce that they will work jointly on a defence against hypersonics. Vladimir Putin said he had hypersonic weapons in 2018. US intelligence says that China has tested hypersonics. Russia is often reported to be using hypersonic weapons in Ukraine. What’s going on?
It’s confusing, because the word “hypersonic” simply means something that goes faster than Mach 5. Weapons have been doing this forever: a normal ICBM warhead is launched on a rocket stack, soars around the world out in space at terrific speed, and then descends through the atmosphere to strike its target at no less than Mach 20. “Kinzhal” air-launched missiles, as used by Russia in Ukraine, are 1980s technology – but they still travel at Mach 10.
The new hypersonics that have people in a tizzy are different. They’re launched like a normal ICBM warhead, but they descend into the atmosphere sooner and travel much of the way to their target in the upper atmosphere in a hypersonic glide. They used to be called “boost-glide” weapons. Old-school ICBM warheads, Kinzhals and so on can steer themselves enough to make a precision strike, but the new class of hypersonics can swerve around much more violently, making it hard to say just where they’re going or what path they will follow. Flying lower than a normal ICBM warhead, they can’t be detected until they get relatively close. All this makes the new hypersonics much harder to intercept than their predecessors.
It isn’t that easy to intercept old-school ballistic missiles, but it can be done. A normal ICBM warhead may be destroyed out in space by shooting one of the USA’s small fleet of 44 Groundbased Midcourse Defense (GMD) interceptors at it, or in some circumstances by Standard Missile 3s (SM-3s) fired from warships with the Aegis combat system. Normal ballistic warheads may also be knocked down during their descent phase by SM-2 and SM-6 interceptors from Aegis ships, or by land-based THAAD and Patriot interceptors.
There has been a long-running effort by US-based peace campaigners such as Theodore Postol to argue that US interceptors don’t and cannot work: and indeed it’s true as Postol points out that there have been many test failures and scandals in the US missile-defence programme. Nonetheless interceptors clearly work to some degree: there have also been test successes, and an SM-3 was used to successfully shoot down a malfunctioning US spy satellite back in 2008. More recently, Patriot interceptors have shot down Kinzhals in Ukraine.
Vladimir Putin, for one, evidently believes that US interceptors work: this is why Russia has produced the Avangard hypersonic nuke. Avangards are launched aboard existing Russian ICBMs such as the Satan II. Xi Jinping is a believer too: China’s hypersonic DF-27 is intended to beat the US Navy’s interceptors to sink US aircraft carriers in the Pacific – if China could find out where the carriers were, anyway.
Thus it makes sense that the US and Japan will work together on the new Glide Phase Interceptor (GPI), intended to be launched from Aegis warships like the various SMs. Japan already makes parts of the existing SM-3, and has Aegis warships to protect itself against North Korean and Chinese ballistic missiles. With GPIs, and the accompanying satellite sensors needed to track incoming hypersonics, the two nations would be able to carry out naval operations within range of China’s future rocket forces – perhaps to help prevent a Chinese invasion of Taiwan.
So it seems pretty clear that actually interceptor technology is difficult but feasible, rather than the impossibility that Ted Postol wants it to be. That’s not necessarily a problem for the US and Russia, both able to put a thousand warheads into the sky, both with hypersonics coming into service, and (in the case of the US) with hypersonics-busting interceptors not too far off. The US and Russia still have effective nuclear deterrents.
The continuing advance of interceptor technology is a problem for some other nuclear nations, though: the ones who don’t have many nukes, some of whom haven’t even got started on hypersonic warheads – let alone got started on effective interceptors of any kind.
Kim Jong Un will be very irritated at the thought that the nascent North Korean nuclear ICBM force has been rendered impotent before it could really get started by US and Japanese SM-3s, GPIs and Patriots. Xi Jinping won’t be pleased that China’s DF-27s and many of its other weapons will struggle to defeat the SMs and GPIs of the US and its allied navies, or the Patriots of Taiwan.
And we in Britain, of course, might feel let down yet again by our defence establishment. We can only throw a hundred-odd warheads and we don’t even have a plan to get hypersonics. The continuing rise of interceptors seriously undermines our national deterrent: Russia’s vaunted S-500 defence interceptor may not be much use against propeller-driven Ukrainian drones, but it is claimed to be good for ballistic missile defence. The Russians also have the preceding A-135/A-235 interceptors: these can be fitted with nuclear warheads, which might compensate for any lack of precision.
And unlike Japan, Canada, Norway, Spain, Australia and South Korea, we Brits don’t have Aegis warships or plans to get any. This is due to our foolish preference for partnering with Europe to reinvent American technology: typically unsuccessfully, at great cost and inevitably using many controlled components from the US anyway.
Not having Aegis ships means we can’t have SMs or GPIs, so we’ll probably never have effective ballistic or hypersonic interceptors. Thus our fleet will be unable to operate off the China coast unless someone else sends some of their proper warships to look after it.
Business as usual, then, at the Ministry of Defence.