Chicago, NYC, LA electrical power grids are targets of N. Korea

No worries about N. Korean being a nuclear threat to the United States (U.S.)?

After all, "the best military in the world" can destroy them on the ground before N. Korea can launch them, right?

What if the warheads are mobile, making them difficult to find prior to launch?

And once launched, where can the bombs be destroyed? Over the Pacific Ocean or over Chicago, Los Angeles, and/or New York City?

Larry Nichols was a former green beret Strike Force commander. According to Nichols, N. Korean's nuclear bombs are difficult to detect before reaching the U.S. That is because these bombs fly seven times higher than U.S. space stations and fly at speeds up to 38,000 miles per hour.

N. Korea's nuclear bombs will knock out electrical power grids if they are destroyed above U.S. air space. How long can people live without electricity before lawlessness and rioting becomes commonplace?