Correction: This story has been updated to correct attribution to Michael Griffin.

WASHINGTON — If military terms can be described as clothing, then hypersonic weapons are the couture, stylish, must-talk-about item of the summer.

The technology behind them. The theory around them. The questions of what competitors are saying and doing with them. Nearly every discussion about future capabilities for America’s defense includes an early mention of hypersonics.

The point man for developing that capability is Michael Griffin, a former NASA administrator who is now the first-ever undersecretary of defense for research and engineering. So when he sat down with reporters July 12 to discuss a range of issues, it wasn’t a surprise hypersonic weaponry came up.

“My view is that this is not an advantage that we can concede to people who wish to be our adversaries,” he said bluntly when asked about the systems. “And there is no reason why we should.”

Here are three key points from Griffin that show his thinking as he helps craft America’s way forward with the technology.

1. Hypersonic weapons' greatest impact are as tactical, not strategic, weapons.

In March Russian President Vladimir Putin made waves when he used an annual speech to unveil what were described as nuclear-capable hypersonic weapons.

But paraphrasing comments by Secretary of Defense Jim Mattis, Griffin noted Russia already has nuclear-capable intercontinental ballistic missiles, so a strategic hypersonic weapon doesn’t change the map much.

Instead, Griffin says, the issue to focus on is the “tactical capability that these sorts of weapons bring to theater conflicts or regional conflicts. Very quick response, high speed, highly maneuverable, difficult to find and track and kill.”

Officials and analysts have noted that hypersonic weapons, thanks to their maneuverability, could be particularly effective as tactical weapons against U.S. naval assets.

2. Space-based defense won’t work.

Griffin is on record as wanting to prototype and develop new kinds of missile defense systems. But he sees no solution based in space that would match up with hypersonic capabilities.

“A space-based hypersonic defense is not a practical approach, in my way of thinking. Even if you had space-based interceptors, it would be technically the wrong way to do it,” Griffin said, due to both the speed of the hypersonic missile and the fact it flies fairly low to the ground.

But space will still play a role in defeating a hypersonic weapon, the same way it does for any sort of strategic asset.

“The utility of space for hypersonic defense is in the indications of warning, the launch detection, the surveillance, acquisition, tracking — the whole arena of persistent global timely awareness,” he said. “You have to do that from space, I don’t know another way to do it. But that is just part of the overall space surveillance task that the DoD has.”

3. The U.S. remains ahead in research, and testing is about to increase.

While there has been a lot of hype around Russia and Chinese investments in hypersonics, Griffin made it clear he believes “we are, have been [and] will remain the world leader in this research area.”

The U.S. could have gone down the path of pursuing more concrete systems, had it wished, Griffin said, but “we didn’t see a need for it. But our adversaries get a vote, and they voted. So we’re going to see their hand and raise them one, in both offensive and defensive capabilities.”

To that extent, Griffin intends to speed up the research and prototyping going into hypersonic weapons, saying there are “capabilities you’ll see maturing through the 2020s.”

“You’re going to see our testing pace stepping up, and you’re going to see capability delivery from the early ‘20s right through the decade,” he added.

But what about China and Russia’s timeline?

Griffin said he’s uncomfortable describing what they have shown off as “operational” at this point, although he acknowledged that the tests have been notable.

“How close they are to operational, I just don’t know. But I’m worried about our end of things,” he said.