Why We Need the Advanced Hypersonic Weapon


While $71 million may not seem like much in Washington, a recent approval of this tidy sum by Congress continues the Army’s rapid development of the cutting-edge boost-glide Advanced Hypersonic Weapon (AHW) missile program. Capable of flying faster than Mach 5 and penetrating enemy defenses, AHW augurs the Army’s re-introduction of a potent and necessary capability into its arsenal: intermediate-range offensive fires. While the program has great promise, a mere few weeks ago, James Acton, a physicist and scholar of strategy, penned a forceful piece contending U.S. boost-glide development programs have “no defined mission” and will kick off an arms race with China. While his piece raises important issues that merit consideration, a correction of the record is necessary, especially given Congress’ support for this program. The United States’ boost-glide development program does in fact have a clearly defined development objective, and will not start an arms race with China — if anything it is a response to Chinese militarization.

Indeed, by swiftly introducing intermediate-range missiles such as the Advanced Hypersonic Weapon in a manner similar to the “Double-Track Decision” taken by NATO during the Cold War, the United States can encourage the global elimination of destabilizing intermediate-range missiles, while ensuring its ability to field them rapidly to enhance deterrence if necessary.

With the ratification of the Intermediate Nuclear Forces (INF) Treaty in 1988, the United States and the Soviet Union eliminated nuclear and conventional ground-launched ballistic and cruise missiles with ranges between 500–5,500 kilometers. The INF Treaty increased strategic stability (by eliminating a potent class of weapons that encouraged swift retaliation) and contributed to a peaceful resolution of the Cold War.

Since then, China has developed the “largest, most active, and diverse ballistic missile program in the world,” building hundreds of the destabilizing and escalatory intermediate-range weapons and aiming them at the United States and its allies. These missiles have contributed to China’s growing anti-access, area denial (A2/AD) capabilities, which as Acton points out, seek to prevent U.S. forces from operating in the Western Pacific, and threaten to upset regional peace and stability.

Specifically, China poses a major and growing threat to U.S. joint operational access in the Asia-Pacific region. Traditionally, the United States has heavily relied on airpower in its power projection and strike concepts of operation. Airpower, however, is increasingly challenged by the dual threats of structured attacks with offensive missiles and of advanced integrated air and missile defense systems (IAMDS).

Consequently, threats against airpower in the First Island Chain (and increasingly the Second Island Chain) are resulting in a greatly decreased potential force gradient. China may be able to effectively target U.S. or allied airbases and defend against the limited numbers of aircraft generated. Additionally, long-range U.S. munitions (such as cruise missiles launched from air or naval platforms) would face mounting difficulty penetrating China’s IAMDS, due to effective defensive sensors, weapons, and networks. The Air-Sea Battle Concept’s unclassified Implementation Summary circuitously describes the situation as: “the nature of heavily defended A2/AD capabilities makes attacking them, either kinetically or non-kinetically, far more challenging.” The U.S. Army Space and Missile Defense Command is more direct: the United States faces a “conventional strike gap.”

The Army can play a leading role in addressing the “conventional strike gap” by developing boost-glide intermediate-range missiles. Fired in salvos from the First and Second Island Chains and equipped with penetration aids, intermediate-range boost-glide weapons would counter enemy offensive effects chains by targeting sites such as high-value space downlink systems, fixed anti-satellite tracking and firing systems, key radars and associated systems, command and control nodes, long-range surveillance systems, and possibly even transporter erector launchers (TELs), TEL reload points, or ships in port.

Boost-glide weapons would excel at penetrating dense IAMDS where aircraft would have difficulty operating. Additionally, if they were mobile and practiced passive defense measures, they would provide the Joint Force with a potentially more resilient means of attack than tactical aviation, which is vulnerable to airbase targeting. On the whole, boost-glide weapons would effectively contribute to the Joint Force’s efforts to counter Chinese A2/AD systems and diminish Chinese confidence in their ability to coerce other countries and wage war.

At the strategic level, boost-glide systems (and other intermediate-range missile systems) may contribute to a cost-imposing strategy against China. By deploying relatively inexpensive offensive weapons such as boost-glide systems, the United States may asymmetrically drive China to invest in more expensive IAMDS, especially those capable of intercepting hypersonic missiles, instead of offensive, power-projection capabilities. Therefore, U.S. boost-glide development is oriented toward clear objectives, and research into hypersonics more broadly should be properly interpreted as a response to China’s rapidly advancing military capabilities, including its massive arsenal of intermediate-range missiles.

Some critics argue the use of boost-glide weapons could escalate a conflict, perhaps even “prompt the Chinese to use nuclear weapons” if its command-and-control system “misread an incoming U.S. boost-glide attack on this system as one intended to disable its nuclear forces.” The gravity of the subject of nuclear escalation merits careful consideration, especially if boost-glide systems gain intercontinental instead of just intermediate range. In fact, it is possible both Russia and China will vociferously protest the development and deployment of such weapons and cite nuclear concerns in order to halt their progress in the United States.

However, there are at least three reasons why this assumption on nuclear escalation is likely incorrect. First, China has a highly secure second-strike nuclear force that boost-glide weapons would be highly challenged to seriously degrade — even if the United States explicitly proceeded to deliberately and systematically target Chinese nuclear forces (another unlikely assumption). Second, it is against Chinese nuclear doctrine to launch on warning; accordingly, China has designed its forces to be able to withstand a nuclear salvo before successfully counterattacking.

Most importantly, though, it is unlikely China would use nuclear weapons in response to U.S. conventional capabilities, such as boost-glide weapons, because China will become socialized to the U.S. weapon systems. There are a number of steps the U.S. Department of Defense can take to effectively address these concerns while successfully introducing this necessary class of weapons. It can, for example, continue to exercise transparency on the development of these systems, and it could announce that it will not co-locate nuclear and conventional ballistic or boost-glide missile systems.

Even more importantly, the United States can introduce these systems in a manner similar to the “Double-Track Decision” taken by NATO during the Cold War. Strategically, the United States can announce that given China’s provocative and destabilizing development of nuclear and conventional intermediate-range missiles, it will develop and deploy similar missile systems (initially INF Treaty-compliant boost-glide weapons) capable of targeting China, unless China agrees to eliminate its own systems. This parallel process would gradually socialize potential adversaries such as China and Russia to this new class of weapon system and its conventional application, would strengthen the credibility of U.S. conventional deterrence, and if China accedes to such a treaty, would be a victory for regional peace and stability and cooperation between the nations.

If however China does not accede to a treaty that eliminates intermediate-range missiles, be they ballistic, cruise, or boost-glide, it would eventually be forced to adopt an approach similar to that likely adopted by U.S. forces. In time of war, U.S. forces would likely not fire a nuclear strike upon warning of launch of Chinese ballistic or cruise missiles, because they know China has conventional missiles in its arsenal and they know the resiliency of the U.S. nuclear triad supporting U.S. conventional forces. If the United States had intermediate-range missiles in its arsenal, Chinese forces would likely adopt a similar approach.

In his critique, Acton raises the point that Chinese boost-glide missiles could reach the United States. In response, it should be noted that China can already strike the United States, including the Territory of Guam, the Commonwealth of the Northern Marianas, and portions of Alaska, with its conventional ballistic missiles. By deliberately increasing the ranges of its ballistic missiles, China now directly threatens U.S. territory and has escalated the potential for major conflict. Furthermore, China likely has both kinetic and non-kinetic capabilities (such as conventional weapons employed creatively, computer network attack, and covert operations) with which to strike U.S. forces wherever they are, whether in Okinawa, Guam, Hawaii, San Diego, or Washington.

This trend toward loss of geographic sanctuary, including in the continental United States, is part of a broader pattern in warfare resulting from increases in the ranges of reconnaissance-strike complexes (a combination of weapon, intelligence, surveillance, and reconnaissance, and network capabilities). Absent some unforeseen disruption, this pattern will only continue to increase. China’s potential introduction of boost-glide weapons is a worrisome development, given their ability to evade many types of missile defense, but it is not a dramatic departure from China’s current course of steady expansion in weapon ranges.

A valuable point critics of U.S. hypersonics emphasize is the importance of policy undergirding U.S. boost-glide developments. As U.S. boost-glide programs have been in a research and development phase, it is understandable that there is a lack of fully articulated, unclassified policy on the aims of the program. Nonetheless, given Congress’ continued funding of AHW, the development of the technology, and the evolving security dynamics, now is the time to act.

Accordingly, the United States should carefully review the new operational realities in the region and acknowledge the clear demand for advanced, intermediate-range missile systems. It should announce that given China’s intermediate-range missiles, it will swiftly develop and deploy boost-glide weapons capable of targeting China, unless it agrees to eliminate its intermediate-range missile systems. Additionally, the United States will review the net value of an INF Treaty in which China can continue to develop intermediate-range missiles (and that Russia may be violating), and potentially develop conventional ballistic missiles as well.

In the near term, the U.S. Army should continue developing the promising and relatively mature AHW program, which has a clear objective. It should also prepare for its swift transition into a formal, accelerated program of record (perhaps through the joint urgent operational need process) that can operationally deploy an actual weapon system within five years. In addition to Army air and missile defense capabilities, the thankfully mature AHW can serve as a crucial Army contribution to the rebalance to the Asia-Pacific and the counter-A2/AD fight.


Timothy A. Walton is a consultant of the Alios Consulting Group, a defense and business strategy firm located in Washington, DC. He specializes in Asia-Pacific security dynamics.


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