What are hypersonic weapons?
Hypersonic weapons travel faster than Mach 5, or a speed of approximately 1.6 kilometers per second. Many traditional ballistic missiles re-enter the atmosphere at higher speed, but hypersonic boost-glide vehicles and cruise missiles (HGV, HCM) follow less predictable paths and are capable of a high degree of maneuverability before reaching their targets. These attributes make attack warning and assessment more difficult for the defender, posing a challenge to existing air and missile defenses. Hypersonic weapons can also be gun-type systems such as electro-magnetic railguns, but these are outside the scope of this article.
What do we know about China’s program and capabilities?
In its 2020 report on Chinese military power, the Department of Defense (DoD) noted the emphasis Beijing has placed on developing and testing hypersonic glide vehicles. This is one element of a robust missile program that has led to the fielding of numerous medium- and intermediate-range ballistic and cruise missiles in support of China’s regional warfighting capability. The same report noted that in 2019 China launched “…more ballistic missiles for testing and training than the rest of the world combined.” Unconstrained by treaty limits to which the United States adhered for decades, the People’s Liberation Army (PLA) has fielded a diverse family of missiles that it believes will create operational advantage in a future military confrontation.
As others have noted, hypersonic systems appeared late in this broader missile program, but are now being developed at an aggressive pace, characterized by a large investment in test facilities and engineering expertise and by frequent testing. China has successfully tested the DF-17, a road-mobile medium-range ballistic missile (MRBM) designed to launch an HGV. The DF-17 has an assessed range of 1,800-2,500 kilometers. Its accompanying HGV, designated as DF-ZF (previously WU-14), is reported to possess a range of 1,600-2,400 kilometers and can achieve speeds of Mach 5 – Mach 10 with high degrees of maneuverability and accuracy. Some reports suggest that China is also considering deploying HGVs on DF-21 and DF-26 theater-range ballistic missiles.
China reportedly conducted successful tests of the Starry Sky-2 (Xingkong-2) hypersonic cruise missile in 2018. This system, believed to have a range of 700-800km and a top speed of Mach 6, appears to make use of an experimental “waverider” design that uses powered flight after launch and creates shockwaves to sustain its lift. In its test phase, the Starry Sky-2 vehicle was sent into space by a multi-stage rocket before separating from its booster for maneuvered flight back to Earth. Some analysts have suggested that this technology could emerge in the mid-2020s as an advanced anti-ship missile.
Little is known about other developmental programs for hypersonic vehicles, but China’s ambitious test program points to the PLA’s intent to field additional capabilities with varied aerodynamic attributes. As an example, in 2015 China reportedly successfully tested a hypersonic unmanned aerial vehicle (UAV), presumably as a future intelligence, surveillance and reconnaissance (ISR) platform. Whether this emerging family of hypersonic vehicles will perform “as advertised” by Chinese government agencies remains to be seen. Arguments that characterize these developments as inherently “game changing” should be assessed cautiously.
What role will hypersonic weapons play?
Regional warfighting. China’s current emphasis appears to be developing and fielding conventionally-armed hypersonic vehicles that can support regional warfighting. This represents a natural evolution of China’s investment in conventional precision strike capabilities dating back to lessons learned from the first Gulf War and the Taiwan Strait Crisis of 1996. While the emergence of hypersonic systems does not alter China’s basic approach to key warfighting tasks, these capabilities will provide enhanced options to rapidly target United States air, land, and naval forces in the Indo-Pacific. The goal would be to impede these forces as they seek to project power and maneuver to block a Chinese military campaign focused on achieving a quick victory or fait accompli.
In support of a counter-intervention objective designed to raise costs for the United States or a US-led coalition, hypersonic systems would be part of the PLA’s broader array of capabilities described by the DoD as “anti-access/area denial (A2AD)” – which include, among other systems, integrated air and maritime defenses and a variety of ballistic and cruise missiles configured for tailored strike missions. While China’s traditional ballistic and cruise missiles would have to contend with US regional missile defenses, US theater forces today and in the near-term have no or limited capability to actively defend against hypersonic vehicles, according to US senior military leaders. Of course, as the United States begins to field its own hypersonic missiles, China’s systems will become more vulnerable to rapid US attack.
Strategic Deterrence. There has been some speculation that China could deploy a hyperglide vehicle with a nuclear payload on its newest intercontinental ballistic missile (ICBM), the DF-41. Were it to do so, this would be a clear indication that China sees hypersonic technology as important to ensure the credibility of its strategic nuclear deterrent by providing the means to overcome US homeland missile defenses. While these defenses today are neither intended nor configured to defeat a large-scale Chinese nuclear missile strike, China could be sufficiently concerned about a possible US “breakout” in missile defenses to warrant developing this hypersonic option for its strategic arsenal. This would parallel Russia’s recent fielding of the Avangard HGV atop an ICBM for this purpose. One analyst notes that a survey of Chinese technical studies on hypersonic systems reveals that roughly one quarter are focused on defeating US missile defenses, while roughly one half concentrate on the development of long-range platforms. This suggests the need to consider Chinese hypersonic capabilities beyond the use of conventional payloads to support regional warfighting.
Another possibility posited by students of Chinese strategic forces is the deployment of a nuclear-armed HGV on China’s JL-2 submarine-launched ballistic missiles (SLBM). These missiles have insufficient range today to pose a risk to most of the continental United States because the submarines on which they are deployed operate on patrol in an area (South China Sea) that maximizes their survivability. Theoretically, a nuclear-armed HGV atop these missiles would expand their range and, presumably, their deterrent effectiveness. This would present significant technical challenges and difficult tradeoffs. But as some analysts have noted, the technical direction of China’s HGV program may support consideration of this option at some point.
Conventional Prompt Global Strike. Some experts also project that over time, China is likely to field conventionally-armed hypersonic vehicles with sufficient range to reach the United States in order to hold at risk key US military assets, critical infrastructure, and other high value targets. Beyond posing a coercive threat to the United States, China’s military leaders may see conventionally-armed HGVs as important to developing a global power projection capability.
What issues are raised by an emerging China-US competition in hypersonic weapons?
If China and the United States are entering what some analysts believe will be an “intense offense-defense competition” in hypersonic systems, a number of questions arise. At the strategic level, stability implications depend on the choices made by Beijing and Washington. If China fields a modest number of nuclear-armed HGVs on long-range missiles to bolster confidence in its ability to deliver a retaliatory strike in the face of US missile defenses, this should not significantly alter the current bilateral strategic balance. An obvious question for the future is how this status quo could change if the United States is successful in developing an active defense capability against such platforms. How might China respond and with what impact on nuclear stability?
More challenging from the US vantage might be a decision by China to field a force of conventionally-armed intercontinental-range hypersonic missiles. Analysts have noted that HGVs for prompt global precision strike could threaten key strategic assets such as homeland missile defense sites and overall provide China with a more flexible deterrence capability. Here the key question is: could this become an effective cost-imposing strategy for China, and how would the United States react to the emergence of such a capability?
Similar dynamics could play out at the regional level, where significant US deployments of theater-range hypersonic systems could begin to impose large costs on the PLA as it works to adapt its integrated air defense systems to a new class of threat. Conceivably, these costs China could divert resources from other capability investments and thereby help the United States maintain an overall favorable balance of power in the region.
But beyond what are likely to be competing cost-imposition strategies lie deeper risks for nuclear stability in the context of regional warfighting. Large inventories of hypersonic vehicles on each side capable of inflicting high levels of damage against critical assets early in a conflict conceivably could offset one another. But just as likely is that one side will achieve an operational advantage that creates pressures to escalate the conflict, including to the possible use of nuclear weapons on a limited scale. To the degree both sides see hypersonic weapons as enabling doctrines of surprise, shock, and seizing the initiative, the widespread use of these systems could create escalation risks even in a war being waged over ostensibly limited political objectives.
The DoD must consider these risks as it develops operational concepts for emerging hypersonic systems and defines its broader joint warfighting concept for China. Research agendas, wargames and exercises, and net assessments must also devote attention to the ways in which hypersonic warfare could shape not only the balance of power in East Asia, but the dynamics of deterrence and escalation, as well.
Paul Bernstein is Distinguished Fellow and Dain Hancock is Policy Fellow at the Center for the Study of Weapons of Mass Destruction, National Defense University, Washington, DC. The views expressed here are those of the authors and are not an official policy or position of the National Defense University, the Department of Defense, or the US Government.