Hypersonic Missiles -Reuters, New York Times and Various

News that China tested a nuclear capable Hypersonic Missile has sparked a great deal of commentary about the dangers associated with this type of weapon and the potential for an arms race between the US, China, Russia and perhaps even other states.

Hypersonic weapons travel in the upper atmosphere at speeds of more than five times the speed of sound. They are a concern in part because of their speed, but also because they can maneuver in flight and could approach the US from virtually any direction, unlike the ballistic missiles the USSR had trained at the US during the Cold War. Add this all together, and you have a weapon that is virtually impossible to stop and significantly reduces warning times. In the opinion of some observers, this represents a strategic “game changer”. https://www.nytimes.com/2020/01/02/opinion/hypersonic-missiles.html

There is some debate however over the real threat posed by these weapons. Although the US and other states would clearly be vulnerable to an attack from hypersonic weapons, some argue the significance is “overblown”. https://slate.com/news-and-politics/2021/10/china-hypersonic-missile-test-alarms.html

The US is already vulnerable to ballistic missiles given the weaknesses of current missile defense technology. Moreover, there is no evidence at this point that hypersonic missiles negate the 2nd strike capabilities of any of the major powers. As long as Washington, Moscow or Beijing could retaliate with nuclear weapons after a hypersonic attack, there is little point in launching a quick strike, no matter how unstoppable it may be. This point is made clear in a recent congressional report on hypersonic weapons:

“Other analysts have argued that the strategic implications of hypersonic weapons are minimal.
Pavel Podvig, a senior research fellow at the United Nations Institute for Disarmament Research,
has noted that the weapons “don’t … change much in terms of strategic balance and military
126 This, some analysts argue, is because U.S. competitors such as China and Russia
already possess the ability to strike the United States with intercontinental ballistic missiles,
which, when launched in salvos, could overwhelm U.S. missile defenses. 127 Furthermore, these
analysts note that in the case of hypersonic weapons, traditional principles of deterrence hold: “it
is really a stretch to try to imagine any regime in the world that would be so suicidal that it would
even think threating to use—not to mention to actually use—hypersonic weapons against the
United States … would end well.”
Hypersonic Weapons: Background and Issues for Congress Congressional Research Service R45811 https://sgp.fas.org/crs/weapons/R45811.pdf

Nevertheless, there are some disturbing aspects to this development. First, even if hypersonic weapons are not a game changer for the United States, some American politicians are treating them like they are: Senator Angus King of Maine claimed hypersonic weapons have “the potential to fundamentally undermine strategic stability as we know it,”. https://www.reuters.com/world/china/biden-says-hes-concerned-about-chinese-hypersonic-missiles-2021-10-20/

If political hyperbole overwhelms sober strategic assessments, we could see an dangerous and unnecessary arms race that adds an extra level of tension to the US’ increasingly volatile relationships with Russia and China.

A second concern is hypersonic weapons may eventually find their way into conflicts and rivalries between regional powers. These states may not have reliable second strike capabilities and given the way hypersonic missiles reduce warning time, the pressure to “use them or lose them” may make regional crises considerably more dangerous. https://www.defensenews.com/global/asia-pacific/2021/03/15/hypersonic-and-directed-energy-weapons-who-has-them-and-whos-winning-the-race-in-the-asia-pacific/