"It would be launched from a place we might not necessarily think they would launch from ... and they can do it at any time of day."
When North Korea test-launched an intercontinental ballistic missile on July 4, the US reportedly had observed Kim Jong Un for 70 minutes before the missile took off.
But when North Korea last tested a missile that experts say could hit most of the US mainland, the country did it in the dead of night from a previously unknown launch site with several Kim look-alikes walking around the site.
According to Jeffrey Lewis and Aaron Stein, experts on missile proliferation who host the "Arms Control Wonk" podcast, this could very well have been a signal to US forces.
"Reports are it was launched from an unusual location in the heart of the country that we'd never seen it before," Lewis said. "I think that was in response to stories that we saw the missile 70 minutes prior to its launch."
"This looked more operational," Stein said. "It would be launched from a place we might not necessarily think they would launch from or have ever seen evidence that they might launch from, and they can do it at any time of day."
Notably, the ground-based midcourse defense, the US's primary line of missile defense, has never been tested at night.
Essentially, if North Korea wanted to hit the US with a nuclear missile, a snap launch in the middle of the night like the one it displayed on Friday would work best, and the US would face a much harder task in stopping it.