Can America's Missile-Defense System Handle China's Hypersonic Threat?

A pair of reports in the Financial Times have set the defence community abuzz with the suggestion that China has tested a new hypersonic glide vehicle, possibly with a fractional orbital bombardment system, or FOBS. Two possible tests—one potentially as early as July 27 and a second on August 13 - involved a Chinese Long March 2C orbital launch vehicle blasting off and flying a south polar trajectory into low-earth orbit. The rocket released a hypersonic glide vehicle that circled the globe in low polar orbit before de-orbiting and landing several kilometers from its target. China claims that it was a test of a spaceplane under its Tengyun program, but the nominated date of July 16 doesn’t match up with the launch activity observed later that month and in August.

FOBS is not a new idea. The Soviet Union explored the possibility of firing ballistic missiles over Antarctica to attack the United States from the south, rather than from the north over the Arctic, during the Cold War. An early system was deployed but soon withdrawn from service when Soviet efforts turned to modernising their intercontinental ballistic missile force and introducing independently manoeuvring multiple warheads, or MIRVs, to complicate US defensive measures. The US considered the idea, but never deployed a FOBS capability, and has always favoured traditional ICBMs that fly over the Arctic.

But FOBS might be back. The Russians have suggested a FOBS capability for the SS-28 Sarmat heavy ICBM that will replace the SS-18 Satan, and now it looks like China may be pursuing a FOBS too, though one that replaces traditional MIRVs with hypersonic glide vehicles. It’s the FOBS–HGV combination that’s new and has led to a lot of guessing by China watchers and arms-control advocates about what the test entailed and what China’s intent is in pursuing such a capability.

A FOBS capability, especially if combined with a highly manoeuvrable hypersonic glide vehicle, would enable the Chinese to circumvent existing and likely planned US missile-defence and early warning systems. They would go through the back door, rather than try to bash down the defended and watched front door. Understanding the architecture of US early warning and defence systems helps illuminate why China would test a FOBS–HGV capability now.

US missile early warning starts with a network of infrared satellites that can detect a launch of an ICBM and track it through its flight. At the same time, upgraded early warning radars at Beale Air Force base in California, Fylingdales in the UK and Thule in Greenland, along with the Cobra Dane phased-array radar in Alaska and a range of other sensors, give radar tracks that cue missile interceptors for a mid-course intercept.

The US national missile defence system currently consists of 40 ground-based interceptors at Fort Greely in Alaska and four at Vandenburg Air Force Base in California, with 20 more to be deployed by 2023. The system is designed to defeat a limited raid from North Korean ICBMs, not a large-scale Chinese or Russian nuclear attack. However, Beijing is clearly anxious about US defensive measures.

For China, the concern driving a FOBS–HGV capability must be that US missile defence will expand and become more effective over time, particularly if an expanded ground-based interceptor force were to be combined with ship-based SM-3 interceptors.

China’s nuclear arsenal is small in comparison with the US’s, though the recent discovery of large fields of missile silos under construction in Xinjiang and Inner Mongolia suggests that China is moving away from a ‘minimum deterrent’ posture and might be debating caveats on its no-first-use policy. Greater numbers of both silo-based and road-mobile ICBMs, if combined with a niche FOBS-HGV component that can strike the US from the south, would certainly overwhelm any likely US missile defence architecture. That would strengthen Chinese deterrence against US non-nuclear strikes against China’s nuclear forces, demonstrating that even an expanded US capability to counter any residual Chinese nuclear retaliation wouldn’t prevent a Chinese retaliation from inflicting massive damage. Of course, even a limited nuclear capability such as the one being developed by the North Korea changes decision-making, so the perceived need for Chinese nuclear expansion is less rational.

Despite hyperbolic headlines in the media, suggesting that this was a ‘Sputnik moment’, a Chinese FOBS capability isn’t a fundamental game-changer in nuclear stability. Yet it’s not unimportant or irrelevant either. The US will need to respond to this increased threat.

President Joe Biden and his administration would be very unwise to now adopt a nuclear no-first-use posture, or a ‘sole purpose’ declaration as part of its nuclear posture review to be released in 2022. Such a stance would dramatically weaken extended nuclear deterrence, and if such a step were made against a backdrop of Chinese (and Russian) nuclear build-up and force posture changes, it would send the wrong signal to allies looking for US leadership and resolve, especially after the debacle of the Afghanistan withdrawal.

Nor should the Biden administration cancel the ground-based strategic deterrent program that would replace ageing Minuteman ICBMs. Any rush to scrap ICBMs and turn the US nuclear triad into a dyad would only make it easier for an adversary to deliver a decisive nuclear blow in a crisis, even if it couldn’t deliver a knockout punch due to US Navy ballistic missile submarines.

The US should look at options for expanding its missile early warning and missile tracking coverage to deal with hypersonic glide vehicles and threats such as FOBS. Continued development of infrared surveillance satellites will be important, including the ‘next-generation overhead persistent infrared’ (known as ‘Next Gen OPIR’) constellation that will eventually complement the current space-based infrared system. Ground-based sensors such as the upgraded early warning radar network could also be expanded to cover southern launch trajectories from China and Russia.

The FOBS–HGV test presents a challenge but also an opportunity for AUKUS. The projected orbital path from China to the US passes very close to the west coast of Australia. One step that Canberra could take would be to offer to host a US enhanced early warning radar in Western Australia as a joint facility to allow Australia to play an even greater role in supporting US deterrence. Such a facility could complement the Jindalee over-the-horizon radar network and be a key sensor in the Defence Department’s integrated air and missile defence project (AIR 6500 Phase 2). But the challenge would be for Australia to act quickly to establish such a facility, rather than make it a decades-long process that renders such a move irrelevant.

Malcolm Davis is a senior analyst at ASPI. 

This article appears courtesy of ASPI's The Strategist and may be found in its original form here.