The Chinese tested a nuclear-capable hypersonic missile this summer, according to recent reporting in the Financial Times, and it’s made U.S. officials anxious. Though Beijing says it was just doing a routine test of spacecraft technology, and though there’s still some uncertainty about what actually took place, U.S. President Joe Biden acknowledges that he’s concerned about the prospect of China having hypersonic weapons. U.S. Senator Lindsey Graham reportedly is warning of a potential nuclear arms race. Why would China have tested this technology, and what are the implications for the U.S. and the rest of the world?

Stacie Pettyjohn is a senior fellow and the director of the Defense Program at the Center for a New American Security. According to Pettyjohn, China may be responding to a buildup of U.S. defense capabilities, fearful about the Americans’ ability to destroy Chinese weapons. But, she says, the reported missile testing isn’t particularly surprising—or alarming as an indicator of China’s ability to attack and damage the U.S. Pettyjohn assumes that some of the reaction from American leaders is sensible politics—a way of raising awareness in their country about Beijing’s ambitions and potential threats to U.S. interests—but she cautions that overreaction can be dangerous. If the U.S. government feels compelled to expand its missile defenses, that may fuel China’s worries, triggering a costly and perilous escalation. In Pettyjohn’s view, the United States should continue to develop its own hypersonic weapons, not as a means of matching China’s every move but as such weapons are specifically needed for American military operations, including to advance nuclear deterrence and global stability.


Graham Vyse: What is this weapon that China reportedly tested, exactly?

Stacie Pettyjohn: Part of the reason it’s complicated to understand what the Chinese tested is they tested two things together. Each is a bit exotic, though neither is completely new technologically.

The first is an orbital bombardment system, which the Soviets developed during the Cold War in response to the U.S. fielding a ballistic-missile defense system. You have a rocket that shoots a missile up into space, where it falls into orbit, follows a shorter route toward its target, then breaks to move out of orbit, falls back down to the earth, and explodes.

The Soviets did this to evade U.S. missile defenses, partly because orbital bombardment systems are harder to detect. They don’t have trajectories that are as easy to project as normal intercontinental ballistic missiles’ are. An intercontinental ballistic missile has to go up and down, and all of the missiles the Soviets had aimed at the U.S.—and vice versa—during the Cold War would traverse the North Pole. If you shoot a rocket and it falls into low-Earth orbit, it can take a longer path, going around the South Pole, which means it can avoid some of the missile defenses the U.S. has and be more likely to reach its target.

Kirill Sharkovski

The second thing the Chinese tested here—and what made it all even more exotic and surprising to some people—was a hypersonic glide vehicle on top. Hypersonic glide vehicles have gotten a lot of attention in the U.S., and the Russians are developing them along with the Chinese. All ballistic missiles fly at hypersonic speeds, but what makes the glide vehicles interesting is that they slow down to maneuver. That increases their survivability and allows them to try to approach their target in a way that would evade different defense systems.

Vyse: So, what was significant about the reported test?

Pettyjohn: In 2017, China successfully tested hypersonic glide vehicles—not an orbital bombardment system but a medium-range ballistic missile with hypersonic glide vehicles. The orbital bombardment piece of the recent test was somewhat surprising to a lot of people, because it wasn’t well understood.

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