Should the U.S. Deploy Hypersonic Weapons?
By Joe Buff, MS, FSA
Some defense pundits see the present world as being in a dangerous nuclear arms control crisis, and some are warning of a new global arms race: The Intermediate Nuclear Forces Treaty between the U.S. and Russia has fallen, as a direct result of Russia egregiously and unapologetically cheating to the tune of several battalions of banned nuclear missiles deployed in Eastern Europe. The New START agreement, which limits America and Russia to 1,550 deployed strategic nuclear warheads each, is due to expire amid doubts about Russia’s willingness to extend it. Meanwhile, China is fast expanding and modernizing their entire military, including tactical and strategic nuclear forces, and they face no arms control limits at all since they have never agreed to any such treaties.
Amid these very valid concerns, yet another has arisen, about the lack of constraints on any countries regarding a new class of weapon delivery platform: hypersonic vehicles, able to tear through the air on their way to the target at speeds approaching Mach 20. Russia, China, and the US are all going after these with one or another degree of unconstrained abandon; successful designs will be astonishingly fast and very hard to see and track before impact. The US has been accused by some American pundits of lacking any coherent policy here: Should we invest in next-gen ways to detect and defend against such weapons, or look instead to deter their use by having lots of our own with which to retaliate in kind, or should we try to get the UN to pass a total global ban?
But hypersonics are a very different issue from the clear and present danger of getting into a renewed arms race in the sheer number of low- and high-yield nuclear warheads in the hands of all three competing superpowers — who are in reality dependent together on mutual nuclear deterrence to keep the strategic peace. Are these new hypersonic delivery vehicles — which are simply speedier and harder to intercept, could mount any type warhead, but don’t themselves add at all to the world total of nuclear warheads — really as bad as naysayers would have us believe?
Ought the U.S. to shun hypersonics — in yet another vain attempt to get our relentlessly anti-democratic, nuclear-modernizing adversaries to go along with our fine example? Should we try to have hypersonics somehow limited or even forbidden by new arms control treaties? Or, in an era when the nuclear-weapons treaties that do exist are under such stress, and where many technologies are advancing faster than can be effectively regulated, should America make sure above all to not fall behind in being able to defend our vital interests on the world stage? And don’t our extended deterrence obligations to our allies, using America’s nuclear umbrella as a check against friends proliferating for themselves, call on us to remain close to, nay, to stay right at the absolute state of the art in putting retaliation-in-kind second-strike nuclear ordnance reliably on target?
What exactly are hypersonics? A hypersonic vehicle is defined as one that moves through the air at a speed of Mach 5 or greater. At sea level, Mach 5 is about 3,500 mph, although hypersonic vehicle designers prefer as much as possible to exploit the much lower air resistance at very high altitude, near or in space. This capability is not exactly new: Germany’s WWII-era V-2 ballistic missiles reached Mach 5, as did the U.S. Air Force’s manned X-15 rocket plane in the 1960s; the reentry vehicles of ICBMs descend ever faster, at top speeds around Mach 16. What is new is the introduction by several competing countries of a next generation of hypersonic weaponry, able to attain speeds as high as Mach 20 and carry a warhead than could be conventional, or nuclear, or that simply relies on its own kinetic-energy smashing power. Crucially, these newer weapons can also maneuver evasively (“jink”) in flight, to avoid the defenses — such as interceptor projectiles or even directed-energy lasers — that work best against the predictable lobbing paths of regular ballistic missiles and their smoothly falling warheads.
The exceedingly fast travel time in flight, mere minutes from launch to target impact across great distances, makes hypersonics effective against fleeting, highly mobile targets that can evade destruction by slower-traveling weapons. Hypersonics are coveted for this ability, as well as for their ability to reliably penetrate through current enemy defensive systems — and perhaps through virtually all conceivable, emerging “missile shield” technologies too.
Russia and China are somewhat ahead of the U.S. in hypersonic weapons development, particularly ones with nuclear warheads. Both countries are heavily nuclear-armed rivals of America in what many experts see as a de facto New Cold War. Both have said they feel threatened by the increasingly effective missile shield systems that America is fielding now with basing help from our allies. Moscow and Beijing complain that our sophisticated defenses — the ground-based embodiment of the spirit of President Reagan’s Star Wars space shield — exceed their own technical know-how, while rendering impotent their ability to deter us from a devastating surprise nuclear attack. They say we could launch all our nukes at them, unhindered, then effectively protect ourselves from any retaliating second-strike they would try to make in revenge. This is nonsense and they surely known it. But our factual argument that America’s missile shield has rather small capacity, intended only to stop a few rogue or accidental ICBM launches, repeatedly falls on deaf ears. Cold wars do feature a serious lack of trust regarding adversary intentions. Hence Russia’s and China’s avid development of nuclear-armed hypersonics, part of their hegemonic, blackmail/intimidation-driven “escalate to win” doctrine — with America in the contest too but lagging somewhat behind, as we much prefer nonnuclear-only hypersonic warheads.
This does sounds like a harmful new arms race, something that all peacekeeping advocates should help try to stop. But is it?
The development of hypersonic weapons perhaps is better viewed as just the latest of countless instances during human history of advancing technology being harnessed for unfortunately warlike purposes. In this ongoing drama of life and death, of prosperity versus destruction, halting the march of scientific and military progress for long has proven well-nigh impossible. Advances in chemistry and physics, in metallurgy and materials science, in math and computer science, in aeronautics and astronautics, have all quickly given birth to parallel see-sawing contests between offensive and defensive weapon systems. The best ever achieved in arms-control negotiations has been to delay things temporarily, to reduce unnecessary excess, to restrict the most egregious types of aggressive assaults, and to reach stability for a time through some semblance of parity — i.e., an assumed rough equivalence in the capabilities and capacities that rival powers possess for damaging each other, so that they can instead deter the outbreak of war via what the media once oversimplified and overdramatized as “mutual assured destruction” (MAD).
In this context, mutual nuclear deterrence has successfully prevented both nuclear war and conventional “big” war between the reigning superpowers for 75 years and counting — in fact, ever since the last super-murderous global catharsis known as World War Two. Mutual confidence in this global peace-enforcing system is vitally important to its continuing effectiveness. If China and Russia supposedly fear that America is gaining a technical edge in nuclear attack, threatening the balance of mutual deterrence, they need to be able to demonstrably restore what they can say with confidence is genuine parity. In that sense, hypersonics are a good thing. After all, America’s current missile shield development is meant to protect us only from a small number of rogue or accidental ICBM launches, not a wholesale retaliatory second-strike from Russia and/or China. And if we by design can’t stop their whole survivable arsenals’ worth of nuclear missiles now, what’s the harm in not being able to stop them when they’re delivered by hypersonics? In short, letting adversaries use new technology to restore what they consider to be a semblance of strategic stability is, well, stabilizing.
Pundits claiming that hypersonic speeds would rush and panic POTUS into ordering a nuclear counter-strike too quickly are badly misinformed: The U.S. follows a strict doctrine of only ever considering a nuclear retaliation based on “launch after attack” rules of engagement. This means POTUS would require thoroughly verified ground truth that a nuclear warhead had actually gone off against us or our allies. Again, this is wisely stabilizing.
That brings us to the question of whether America should develop hypersonics. The only correct answer is “Definitely yes,” and we need to be in the lead here.
We need to address two separate (but equally significant) applications of hypersonics by the U.S., one conventional and one nuclear. These two applications would go a long way to de-fuse the downside of having our adversaries one-sidedly field hypersonics; they would open up for our benefit some of the upside; and they would maintain strategic parity and stability until such time — if ever — when diplomatic negotiations could lead to ratified hypersonics arms-control treaties after all.
The conventional-arms use is to implement Prompt Global Strike, something DOD has sought for at least twenty years. A pinpoint high-value target that is mobile and fleeting — such as a rogue state’s missile-carrier vehicle dodging in and out of a cave or tunnel, or a known and wanted terrorist leader suddenly surfacing for a war council — demands a way for U.S. forces to go from target identification to launch authorization to weapon impact in an hour or less — or the opportunity will be lost, at great cost to our side. Conventional hypersonics offer us a way to achieve this important defensive goal without undue risk of collateral damage or escalation. The same conventionally-armed hypersonics capability would also better sustain our conventional deterrence against superpower adversaries, who might otherwise be more likely to use such weapons against us (or our allies).
If we lacked them, a crafty enemy might hope to game into our sub-nuclear-threshold combat vulnerabilities, much as Vladimir Putin espouses “escalate to win” in the tactical nuclear arena. Putin’s whole theory of this is deeply flawed, based on it is on badly underestimating America’s determination to punish any enemy use of nukes with our own nukes, at the same time decisively dissuading any further such uses or copycats. Maybe Putin read too much into President Obama’s seemingly squeamish, overly anti-nuclear 2010 National Nuclear Posture Review Report. Any misconception about U.S. willingness to use our nuclear arsenal if ever forced to is convincingly dispelled by President Trump’s very different 2018 version.
The nuclear-arms application of hypersonics by America is as a mirror image to the weapons our New Cold War adversaries are introducing themselves, namely, hypersonic nuclear delivery platforms that can maneuver to get past modern defensive-interceptor systems. The relevant war-and-peace working principles here are two very familiar ones: the need to deter by being able to retaliate in kind, and the need to hedge our deterrence against breakthroughs in enemy capabilities. In fact these two time honored principles blend together when it comes to smart policy for acquiring hypersonics: Given that adversaries might harness their ever-improving maneuverable hypersonics to create defensive weapons that can then reliably intercept our incoming ICBMs, the continuing effectiveness of America’s nuclear deterrence relies on us staying abreast with such weapons systems. We need to make absolutely sure — in the unlikely event our strong deterrence ever fails — that our retaliatory second strike can reliably penetrate even the most advanced enemy missile shields imaginable.
But to do that, our national leadership has to be alive and in communication to be able to order the counter-strike. Some defense analysts rightly warn that a conventional hypersonic projectile, given its unstoppable speed of attack and lack of warning time, could be used to start a “bolt from the blue” nuclear war — by first delivering a stealth-trajectory conventional (kinetic or high-explosive) decapitating strike against America’s commander in chief at a moment of his or her exposed vulnerability. Then, while our nuclear command-and-control is still paralyzed by POTUS’s sudden demise — or so this worrisome doomsday scenario goes — the rest of our top brass and our land-based nuclear assets can be devastated by nuclear attacks with relative impunity. (Our SSBNs on patrol would be immune to the hypersonic weaponry, but not to the crippling of the launch-order process.) But trying to ban all the world’s hypersonics to prevent this is quite likely to be a losing proposition.
A better solution would address the problem of decapitating strikes head-on (pardon the pun), by providing now for more than one senior civilian government official who can give limited nuclear launch orders in specified, dire-enough circumstances, in case POTUS is verified to be knocked out of action. And a good way to deter in advance any adversary attempts at such non-nuclear hypersonic decapitation would be to amend our National Nuclear Posture to declare that we would retaliate, at our sole option, with a nuclear counter-strike — just as we say we would do now for various enemy weapons of mass destruction (WMD) strikes such as biological, chemical, dirty/radiological, electromagnetic pulse, and cyber weapons.
Another concern about hypersonic vehicles is that they approach their target at a lower altitude that the lobbing mortar-shell-like trajectory used by ICBMs and SLBMs. The latter can be detected way off by the right type of ground-based radar, looking way above and beyond the horizon. And hypersonics fly at altitudes higher than those used by traditional cruise missiles and attacking aircraft, thus exploiting a “donut hole” in existing air-defense surveillance radar systems. Again, the solution is not some quixotic push to try to get all hypersonics banned — even if such a treaty ever saw multilateral ratification, there would be cheaters just like Russia cheated for years on the Intermediate Nuclear Forces Treaty. What does make sense, and what the U.S. is starting to do, is look at effective ways to plug the donut hole — using constellations of look-down surveillance satellites.
In summation, it is precisely the unfailing reliability of our promised nuclear retaliation-in-kind which assures that our nuclear deterrence will not fail — just as it has not once failed in 75 rather strife filled and technologically innovative years. Our national defense policy for hypersonics should be for the U.S. to give international nuclear and conventional arms control all the attention it deserves while making sure to remain at the cutting edge of these advanced aeronautic capabilities.