How to neutralize North Korea's nuclear threat....

In the past two months, the calculus of the threat from North Korea has fundamentally changed. North Korean leader Kim Jong Un has demonstrated a missile that could reach most of America, has detonated a thermonuclear bomb at least 20 times more powerful than the one used on Hiroshima and has shown credible evidence of miniaturizing a nuclear weapon to fit atop an intercontinental ballistic missile. The Kim regime, once a regional threat, has now become a clear and present danger to the U.S. and to the stability of the world.

The unpalatable choices for President Trump are little different from those of his predecessors: more diplomacy, more economic sanctions or preventive military attacks on North Korean nuclear and missile facilities. These choices range from dangerous to demonstrably futile.

Diplomacy with North Korea has a decadeslong record of bipartisan failure. As Kim's nuclear weapons program continues apace, North Korea has no incentive to negotiate and has made it clear that denuclearization is off the table. The U.S. has nothing new to offer and no pressure to impose.

PHOTO: A North Korean soldier looks through the window of the building that sits on the Demilitarized Zone (DMZ) in Panmunjom, South Korea, that separates the two Koreas, July 21, 2010.
SLIDESHOW: The seesaw relationship between North Korea and the US
Nor will current approaches to economic pressure be effective without cooperation from China — which is unlikely, given that it has a vested interest in the stability of the Kim regime. Recent U.N. sanctions were so restrained by China that even Trump called them “not a big deal.” As Putin commented, the North Koreans will “eat grass” if they have to.

Traditionally, where diplomacy and sanctions fail, military force begins. But because there is so little good intelligence, any preventive attack on North Korean nuclear sites would undoubtedly miss critical elements of the program. More worryingly, a direct attack would risk igniting a devastating war on the Korean Peninsula that might include the exchange of thermonuclear weapons, even Kim’s firing of a salvo of nuclear weapons at the continental U.S. in desperation.

Yet doing nothing — allowing him to threaten the world and proliferate nuclear weapon technology to dangerous regimes such as Iran — is unacceptable.