North Korea’s launch of its new Hwasong-18 intercontinental ballistic missile (ICBM) last week attracted little attention from global media. This is understandable since the world has become accustomed to the DPRK's regular ballistic missile tests over the past decade.

But the Hwasong-18 is a big deal. Solid-propellant missiles like the Hwasong-18 require far less time to launch. Preparations can take mere minutes, making it more challenging to destroy the missile on the ground before it accelerates toward its target, and this substantially heightens the vulnerability of U.S. cities to a North Korean nuclear strike.