An artist’s impression of a Hyper Glide Vehicle. Photo Credit: Forbes
By: Madison Creery, Columnist
Since the 1945 atomic bombings of Hiroshima and Nagasaki, the mere suggestion of the offensive use of nuclear weapons has received instant global condemnation. Luckily, the strategy of deterrence, underpinned by the concept of Mutually Assured Destruction (MAD), has thus far prevented the use of the world’s deadliest weapons. Neither the United States, nor its nuclear opponents, will likely risk nuclear war when adversaries possess the ability to survive the first-strike, then counter with massive retaliation.[i] However, the future viability of MAD may well depend on the actions of the U.S. and Conventional Prompt Global Strike (CPGS), a program that would allow the U.S. to strike any target on Earth within an hour.[ii] Here’s the catch: it involves placing conventional warheads on hypersonic missiles, vehicles that normally carry nuclear weapons. In a world wrought with uncertainty, there is no room for error. Instead of safeguarding U.S. security, these weapons could inadvertently increase the likelihood of nuclear war. While hypersonic missiles provide certain benefits, including the ability to bolster the deterrent effect of existing nuclear arsenals and reduce the need of forward-based forces, CPGS could also have substantially destabilizing effects on the current nuclear balance.[iii]
What’s the Big Deal with Hypersonic Missiles?
According to U.S. Defense Secretary Jim Mattis, hypersonic weapons, such as cruise missiles and Hyper Glide Vehicles (HGVs), will change the character of war forever.[iv] Although it seems this is said about every new weapon released by the military, hypersonics may actually live up to the hype. HGVs will successfully exploit a vulnerable gap between novel offensive missile capabilities and a nations’ current defensive shields and missile interceptors.[v] With nothing to stop the missile from reaching its target, the threshold for the offensive use of force may significantly decline.[vi]
HGVs sit on top of ballistic missile boosters. After the missile’s engine has finished reaching peak velocity, the HGV is released and begins to “glide” to its target on top of the upper atmosphere.[vii] Its uniquely low trajectory keeps its position near-impossible to identify, flying outside the zone of detection of most modern air and missile defense systems. It is estimated that a radar operating from land would not be able to detect the HGV until roughly six minutes to impact.[viii] Further, hypersonics are maneuverable mid-flight.[ix] Even if they could be detected, their trajectories are unpredictable and can avoid opponent’s missile interceptors.[x]
Furthermore, hypersonics can travel at Mach 5 (roughly one to five miles per second), allowing a state to hit any target in the world within an hour, dramatically decreasing an opponent’s time for decision-making.[xi] When considering these advancements in missile weapons technology, it is understandable why the U.S. has placed hypersonics as one of its top development priorities.[xii] However, the way in which the U.S. plans to use hypersonic missiles differs greatly from its adversaries.[xiii] For Russia and China, as the United States’ primary hypersonic competitors, the use of hypersonics can bolster the deterrent effect of their existing nuclear arsenals.[xiv] A weapon that can raise the perceived costs of war, thus causing an enemy to think twice before launching an attack, is a weapon to invest in. However, the U.S. is currently considering using HGVs with conventional warheads.[xv] While the use of nuclear weapons paired with hypersonic delivery systems remains constrained within the MAD framework, it remains unclear how the introduction of conventional munitions may affect state calculations.
CPGS: The Good, The Bad and The Ugly
Hypersonic missiles have potential beyond the nuclear realm. They could provide states, like the U.S., with additional conventional power projection capabilities.[xvi] The U.S. already has forward-based forces across the globe. With hypersonic missiles, however, it would not have to rely on these forces to reach its target. Secretary Mattis has stated his concern that U.S. military forces are not strong enough to protect key U.S. national security interests from all possible threats in the world.[xvii] Hypersonic missiles would allow the U.S. to accomplish just this. This weapon has the ability to eliminate a high-value, “fleeting” target within the hour located deep within enemy territory.[xviii] These weapons are also much faster than the days – or even weeks – needed to plan and execute the same action with forces already stationed in the area. Finally, there is the benefit of reducing U.S. reliance on its number of deployed strategic nuclear weapons by instead using conventional warheads on HGVs.[xix] Yet, there remains one glaring issue: warhead ambiguity.
When the delivery vehicle of a conventional warhead becomes indistinguishable from that of a nuclear weapon, opportunities for miscalculation arise. Warhead ambiguity is when an incoming CPGS weapon is misidentified as carrying a nuclear warhead instead of a conventional one.[xx] This could theoretically lead to the targeted nation ordering a nuclear response before determining the payload of an incoming missile.[xxi] This is especially true when modern-day defense systems are not yet advanced enough to detect an incoming HGV until the last moments of its trajectory.[xxii] Hypersonic missiles encourage hair-trigger tactics, with nations adopting “launch-on-warning” postures to best assure their security. By making the start of a conflict “easier” with the deployment of conventional warheads on HGVs, the U.S. may actually increase the likelihood of nuclear war. Both Russia and China have expressed their fears of the U.S. having the capability to launch a disarming first strike without ever crossing the nuclear threshold.[xxiii] To counter such an offensive advantage, Russia and China have begun investment in similar hypersonic missile programs, with Russia set to complete the world’s first HGV by 2020.[xxiv] This spiral of escalation will likely continue as each country seeks to gain an advantage over the other.
Traditionally, MAD has kept the debate over the viable uses of nuclear weapons in a largely theoretical realm. Now, however, it seems more likely that the U.S.’s CPGS could make nuclear war a reality. Despite the benefits of the program, the U.S. should seriously consider the negative consequences of these weapons for its own deterrence strategy. Policymakers should weigh the genuine likelihood of the U.S. facing a sudden, unanticipated conflict, with no time to build up its forces in the area, before pursuing CPGS. In the final analysis, the U.S. pursuit of the “conventional” in CPGS may be a matter of technological opportunism over mission need, with potential nuclear consequences. Therefore, while it does not need to stop its pursuit of hypersonic missiles, the U.S. must reconsider the intended purposes of the program.
[i] Col. Alan J. Parrington, “Mutually Assured Destruction Revisited: Strategic Doctrine in Question,” Air and Space Power Journal, Winter, 1997, 6.
[ii] Amy F. Woolf, “Conventional Prompt Global Strike and Long-Range Ballistic Missiles: Background and Issues,” Congressional Research Service, 2018, 1.
[iv]Jim Mattis, “Department of Defense Budget Posture,” United States Committee on Armed Services, April 2018, https://www.armed-services.senate.gov/hearings/18-04-26-department-of-defense-budget-posture
[v] Eleanor Peake, “Hypersonic Missiles are Coming to Change Warfare Forever,” Wired, October 2017, https://www.wired.co.uk/article/this-is-how-hypersonic-missiles-could-change-the-future-of-warfare.
[vi] Woolf, “Conventional Prompt Global Strike”, 32
[vii] James M. Acton, “Silver Bullet: Asking the Right Questions About Conventional Prompt Global Strike” Carnegie Endowment for International Peace, 2012, 6.
[viii] Speier, Richard H., George Nacouzi, Carrie A. Lee, and Richard M. Moore. “Hypersonic Missile Nonproliferation: Hindering the Spread of a New Class of Weapons,” RAND Corporation, 2017, 11.
[ix] Woolf, “Conventional Prompt Global Strike” 10
[x] Ibid, 112.
[xi] Woolf, Conventional Prompt Global Strike, 1
[xii] Mattis, Department of Defense, 2018
[xiii] Acton, “Silver Bullet”, 1
[xiv] Ben Brimelow, “Russia, China, and the U.S. are in a Hypersonic Weapons Arms Race – And Officials Warn the U.S. Could be Falling Behind,” Business Insider, April, 2018, https://www.businessinsider.com/hypersonic-weapons-us-china-russia-arms-race-2018-4.
[xv] Woolf, “Conventional Prompt Global Strike”, 2012, 1
[xvii] Department of Defense, “Actions Needed to Address Five Key Mission Challenges,” U.S. Government Accountability Office, July 2017, https://www.gao.gov/products/GAO-17-369
[xviii] Woolf,” Conventional Prompt Global Strike”, 2.
[xix] Ibid, 8
[xx] Ibid, 8
[xxi] Acton, “Silver Bullet”, 112
[xxiii] Ben Brimelow, “Russia, China, and the U.S. are in a Hypersonic Weapons Arms Race,” 2018.