Hypersonic Weapons: Strategic Asset or Tactical Tool?

As the Pentagon moves ahead in its pursuit of hypersonic weapons, the defense community has mixed opinions on whether the new missiles should be considered as strategic assets—driven by the principle that simply owning them should dissuade adversaries from using their own, and would be devastating if deployed.

Those discussions could shape how adding hypersonic weapons to the inventory could affect the broader strategic deterrent as the nuclear triad is modernized in the coming decades.

Gen. Paul Selva, vice chairman of the Joint Chiefs of Staff, noted at a recent Strategic Deterrent Coalition conference that hypersonic weapons would be incredibly versatile in a conventional or nuclear conflict.

“The best layman’s description I’ve heard of hypersonics as a strategic threat goes something like this: If you’re going Mach 13 at the very northern edge of Hudson Bay, you have enough residual velocity to hit all 48 of the continental United States,” Selva said April 25. “You can choose … to make a right or a left turn and hit Maine or Alaska, or you can hit San Diego or Key West. That’s a monstrous problem.”

On the other hand, Pentagon research chief Mike Griffin told reporters last July he views hypersonic missiles more as tactical weapons, not strategic. DOD should hone in on the “tactical capability that these sorts of weapons bring to theater conflicts or regional conflicts,” Defense News reported. “Very quick response, high speed, highly maneuverable, difficult to find, and track, and kill.”

Experts say hypersonic weapons could fly one mile per second and could take 15 minutes or less to reach a target, compared to about half an hour for a ballistic missile. James Acton, co-director of the Carnegie Endowment for International Peace’s nuclear policy program, says a hypersonic missile would move slower when approaching its target than a ballistic missile at the same range.

The Air Force aims to develop hypersonic weapon prototypes in the next few years under rapid development and acquisition partnerships with the Defense Advanced Research Projects Agency, its sister services, and Lockheed Martin. Some have speculated that development should run parallel to the Pentagon’s broader nuclear modernization effort.

“Don’t presume that what you modernize in this next five to seven, eight, 10 years stays the same for the rest of its deployed life,” former 20th Air Force commander retired Maj. Gen. Roger Burg, who now runs O’Malley Burg Consulting, said at a recent AFA Mitchell Institute breakfast. “Hypersonics are going to have to be part of the nuclear deterrent of the future.”

Hypersonics’ role in projecting strategic power depends on how the military defines how they will be deployed. Possible missions include preemptively disabling rogue states’ nuclear infrastructure or attacking anti-satellite weapons before they could be used, Acton said.

“I’m not sure we’ve got a clear concept of operations,” Acton said in a May 6 interview. “A lot of this is developing technology for the sake of technology and trying to work out what to do with it later. To the best of my knowledge, we’ve never articulated precisely what mission need hypersonics are supposed to fill.”

Hypersonics could pose tactical conundrums as well, according to Selva, who admitted he isn’t sure yet what that capability could mean in a “launch under attack” scenario like those considered during the Cold War. The US has to consider what it means to add weapons that would go undetected by current missile-warning systems, he said.

“We see a thousand missiles coming our way, we got a thousand missiles pointed their way, it’s the end of the world as we know it. … Some modicum of the nation survives, we live to fly and fight another day,” he said. “Hypersonics really complicate that problem in some really difficult tactical and operational settings. We have to figure out how to adjust to those.”

Acton disputes that fielding American hypersonics will directly offset Russian or Chinese hypersonics, and that the US shouldn’t pursue the capability simply because its rivals are.

He argues a conventional hypersonic missile strike would be 100 or 1,000 times less powerful than a nuclear one, and that such comparisons of hypersonic and nuclear weapons are “totally misleading.”

“I would still class certain kinds of hypersonic weapons as strategic,” he said. “In particular, we have a lot of military hardware deep in the US that we’ve never had to worry about being attacked with conventional weapons before. … If Russia to China had the ability to reach out over very long distances and threaten that kind of critical military infrastructure within the US, that’s a pretty significant development.”

While he said very long-range hypersonic missiles could be considered strategic, he added putting a nuclear warhead on them wouldn’t necessarily be a game-changer because the US is already vulnerable to a nuclear attack.

Nuclear-tipped or not, some leaders already think of hypersonic missiles as linked with the nuclear arsenal. US Strategic Command boss Gen. John Hyten, who is nominated to take Selva’s spot among the Joint Chiefs, told senators earlier this year America’s nuclear deterrent is its defense against such weapons.

Hyten also argues hypersonics wouldn’t be covered by the 1987 Intermediate-Range Nuclear Forces Treaty because less than half the trajectory would be ballistic, or following an arc like a fly ball. However, Acton said that because Russia may field its dual-use Avangard hypersonic boost-glide vehicle on an existing intercontinental ballistic missile, Avangard would already be covered by the 2010 New START treaty—meaning it would count toward the limits on how many warheads and delivery systems the US and Russia can deploy at once.

“I just don’t see hypersonics displacing the kinds of things we would think about using nuclear weapons for,” Acton said. “They’re just completely different categories. … I don’t think we can get rid of some nuclear weapons because we in some way substitute or replace them for hypersonics.”