Isozaki said the North’s shortage of oil has largely incapacitated its conventional military, which he said poses “virtually no threat” to neighboring countries although it is the world’s fourth-largest.

If the North were to unleash its military, it would face a much stronger set of opponents than it did in 1950.

South Korea, where military service is mandatory, has roughly 670,000 in its armed forces. The United States has 28,000 troops in Korea, and another 50,000 in Japan.

U.S. fighters can reach North Korean airspace from their Japanese bases in about 30 minutes, and two U.S. navy destroyers are “tethered” to the North, meaning they are either in the Sea of Japan or on call to be there quickly if needed.

The United States also now has a nuclear-powered aircraft carrier permanently based in Japan, and has a squadron of F-22 stealth jets — the most advanced in the Air Force — deployed to the southern island of Okinawa.