A New Phase Opens on North Korea; Is the U.S. Ready?

A tricky new phase in the world’s most dangerous problem, the standoff over North Korea’s nuclear program, has just opened. The U.S. had better be ready.

But is it?

That question arises now that South Korean President Moon Jae-in has dispatched a high-level delegation to North Korea to open a new diplomatic path, and North Korean leader Kim...