North Korean nuclear and missile capabilities pose the most serious security threat facing South Korea and the United States. Now, with a preemptive strike by the U.S. on the table, the threat is even more dangerous.

Why is this? The answer lies in the proximity of North Korea to Seoul. Weapons can rain down on the city within minutes, or terrorists could infiltrate via the DMZ, if the U.S. chooses to attack the DPRK.

Having served two tours in Korea, the second as commander-in-chief of all U.S. combined forces for almost three years, I have some appreciation of the situation,