North Korean dictator Kim Jong-un’s paranoid megalomania drove him to develop nuclear missiles while his nation ate grass. Almost certainly, he will not denuclearize peacefully.

But what little hope there might have been for peaceful denuclearization has been betrayed by a Democratic Party already surrendering to Kim Jong-un.

Democratic national security experts, including Susan Rice, President Obama’s National Security Advisor, former Director of National Intelligence, Gen. James Clapper, and many others declare we must learn to live with a nuclear-armed North Korea, and accept a Mutual Assured Destruction (MAD) relationship withKim Jong-un.

MAD kept the peace during the Cold War with the USSR, and will work with North Korea too, or so they reason.

Joel Mathis in The Week recently re-articulated the view of liberal journalists and the Democratic Party:  “For more than a generation, American policy towardNorth Korea has been aimed mostly at keeping that country from obtaining or keeping a nuclear arsenal. That mission failed in 2006, and American presidents have been scrambling ever since to obtain denuclearization. That goal has never been achieved, and there is no reason to believe it ever will be.”

Mr. Mathis, who describes himself as no fan of President Trump, praises the president’s performance at the Hanoi nuclear summit, which he interprets as manifesting a decision “to live with the weapons, pursue peace, and find a way to declare victory anyway even if he still talks about denuclearization” of North Korea.

Mr. Mathis: “Kim is unequivocally a bad guy. But the United States has done business with villainous nuclear states before — we practiced detente with the Soviet Union. The Cold War stayed cold, by and large.”

Why should North Korea agree to peaceful denuclearization when the Democratic Party, representing half the U.S. electorate, and their “mainstream” media allies, have already surrendered so vociferously to living with a nuclear-armed North Korea?

Why should North Korea agree to peaceful denuclearization with President Trump, when Democrats may in 19 months capture control of the White House and Senate?

Surrendering to a Mutual Assured Destruction relationship with Kim Jong-un — because of North Korean aggression or miscalculation — sooner or later will kill millions of Americans.

Those who think MAD made for a relatively stable and safe relationship between the United States and USSR don’t know the history of the Cold War.

MAD nearly failed over a dozen times. A few of these brushes with nuclear Armageddon during and after the Cold War are recounted in my book “War Scare: Russia and America on the Nuclear Brink.”

Yet the U.S.-USSR bipolar Cold War was relatively more stable and safer than the emerging multi-polar nuclear threat environment today, where Russia, China and North Korea can all deliver doomsday against the United States.

If we are lucky, increased likelihood of nuclear war with more nuclear-armed actors is merely additive. So compared to the Cold War, the triple threat from Russia, China and North Korea increases likelihood of nuclear war “merely” threefold.

However, more sophisticated dynamic threat analysis, accounting for possible interactions and cascading miscalculations between actors (such as those that resulted in World War I) suggests pathways to nuclear war are not additive — but exponential.

Thus, addition of North Korea to Russia and China as nuclear threats would, compared to the bipolar Cold War, increase pathways to Armageddon by nine-fold.

But even these cold calculations understate the danger, because the actors themselves are more dangerous, especially so in combination:

• Russia is a failing military dictatorship seeking confrontation to control its population whose greatest asset is nuclear weapons.

• China is a rising totalitarian hegemon challenging America for world leadership through conventional and nuclear forces.

• North Korea, perhaps most dangerous, a failed theocracy dedicated to the worship of Kim Jong-un, impoverished and weak, what political scientist Yehezkel Dror would call a “crazy state”— yet a military super-power because of nuclear missiles.

So our present international system includes in Russia and China two national archetypes (like nuclear-armed versions of the Austro-Hungarian Empire and Nazi Germany) that historically start world wars.

North Korea is a threat unprecedented in history. Never before has a state such an utter failure and so dysfunctional been able to threaten great powers — until today with the advent of nuclear-armed North Korea.

North Korean elites are less predictable and more aggressive than Russia and China. Pyongyang launched the Korean War when it had no nuclear weapons, when the United States had an overwhelming preponderance in military power.

Pyongyang only agreed to cessation of fighting, not peace, in the Korean War, because President Eisenhower threatened to use tactical nuclear weapons.

Kim Jong-un started threatening nuclear strikes against the United States in 2013, shortly after orbiting North Korea’s first satellite. He eagerly sought nuclear confrontation with President Obama and President Trump.

Another new factor — electromagnetic pulse (EMP). EMP attack could be executed by a single nuclear-armed North Korean satellite, blacking-out North America and ending our civilization.

North Korea is like a vengeful psychopathic bully armed with a .44 Magnum. They will not be disarmed peacefully. Forcibly denuclearizing North Korea is risky, but the alternative will be fatal.

• Dr. Peter Vincent Pry, former chief of staff of the congressional Electromagnetic Pulse Commission, served on the House Armed Services Committee and the CIA.