Out of all America’s massive foreign policy challenges — China, Russia, the Middle East, to name only the most obvious — North Korea is perhaps the least tractable. For a quarter century, Washington has tried both engagement and isolation, but the Hermit Kingdom’s behavior has remained unchanged, except that it is now a nuclear power and could develop an arsenal to match Israel’s or Pakistan’s fairly soon.

That’s not good news, but it’s not as bad as it seems. The tyranny in Pyongyang has never been and doesn’t pretend to be a global power competing with Washington. It aims its rhetoric and weapons at America simply because we’re the superpower on its border. War with Pyongyang poses an existential threat to the Republic of Korea, but it’s a matter of choice for Washington.

North Korea has existed longer than the People’s Republic of China and almost as long as the Soviet Union did. It emerged from the rubble of the Second World War after Japan’s defeat. Washington and Moscow divided the Korean peninsula between them with each occupying approximately half, and created two client states — both authoritarian, aggressive, impoverished and dependent. The Soviets armed the north, headed by former guerrilla leader Kim Il-sung, but Washington denied the republic equivalent arms because President Syngman Rhee threatened to use them in a march north. The Korean War began barely five years after Hiroshima was destroyed, and it was greatly prolonged by China’s joining in and fighting alongside the north.

Millions died or were displaced, both Koreas’ economies were wrecked, and the peninsula was devastated. As the Cold War deepened, the so-called Demilitarized Zone along the 38th parallel dividing north and south, became the most heavily militarized frontier on earth. The two Koreas fell into their own cold war, with occasional hot-war flare-ups, and it has lasted long after the point at which the original Cold War is regarded as ancient history by the millennial generation. Yet America reluctantly remains in the middle of it all.

Kim Il-sung created the most totalitarian state on Earth, with a suffocating personality cult, a system of social classification and a security apparatus that continues to mete out barbarous punishments to the many people whom the regime deems to be its enemies. At one point, North Koreans were sorted into 51 different categories, and 150,000 or more were imprisoned in labor camps. At least half a million people died of starvation in the late 1990s.

Some outside observers hoped Kim’s successors would lift the tyranny, but it has persisted as brutally as ever through the regimes of his son and now his grandson. Political repression is harsher than ever and escape to China is more difficult. People no longer are starving, but obtaining adequate food remains a challenge for many.

North Korea is not much better a friend than it is a foe. Neither Moscow nor Beijing has found it a predictable partner. Kim Il-sung cemented his control by purging Koreans aligned with either of his communist allies. He criticized minimal reforms in Russia after Stalin, and was scathing about China’s for the Cultural Revolution. He vilified Moscow for recognizing the south after the end of the Cold War, although of necessity it reluctantly accepted China’s normalization of relations with Seoul. Until recently, North Korea’s had virtually no relationship with Russia, and ties with China are increasingly strained.

North Korea has evolved into a communist monarchy, with Kim Jong-il succeeding his father in 1994, and being followed by his third son, Kim Jong-un, in 2011. What do we know of Jong-un? That he briefly attended school in Switzerland and is apparently a fan of the Chicago Bulls basketball team (hence his apparently-reciprocated fascination with Dennis Rodman).

Although the despots have routinely inflicted horrors on the populace, they have until recently given some measure of security to their courtiers. Once Kim Il-sung had destroyed opposing factions, those around him were largely loyalists, many of whom had served with him against the Japanese. Officials rose and fell, and some occasionally suffered from mysterious deaths. But public executions, especially of family members, were rare.

But Pyongyang politics now appear to have become far bloodier. Defense Minister Hyon Yong-chol was executed recently, ostensibly for falling asleep at meetings. His fate, both quick and unexpected, suggested something more serious, however, such as involvement in plots against the younger leader.

At least half of North Korea’s top 218 officials have been shifted since Jong-un came to power. Most of those who carried Kim Jong-il’s coffin have disappeared. One of three “regents” created by Kim Jong-il for his son, Vice Marshal Ri Yong-ho, unexpectedly “retired” after an unusual Presidium meeting in July 2012. He is rumored to have been imprisoned or murdered. Jang, another “regent,” was charged with treason and quickly executed. Aunt Kim Kyong-hui, the third “regent,” has disappeared.

Overall, some 500 officials have been executed since Kim Jong-un took power, 70 of them high-level. Fifteen have been killed so far this year. While the sheer numbers are significant, so too is the fact they many have been made public.

A Hong Kong newspaper claimed, falsely, that Uncle Jang was fed to a pack of starving dogs. Minister Hyon was said to be shot with an anti-aircraft gun. The Hermit Kingdom has been a land in which the improbable is actually fairly likely. But there are also many false ideas about the place, because reliable information is so scarce. After I first visited more than two decades ago, for example, a State Department official asked me if North Koreans wore socks. (The answer was yes).

A supposedly knowledgeable analyst once claimed that trucks were not allowed in Pyongyang when in truth they are more common that normal cars. The story about the execution by hungry dog pack was invented as satire. The anti-aircraft fire story reflects one interpretation of satellite photos, not reliable eye-witness accounts.

Jong-un’s behavior sustains the belief that he is impulsive. He appears to be either uniquely cruel or fearful, perhaps both. After consolidating power, his grandfather was able to relax a little. Il-sung’s son, Jong-il, was also secure before succeeding his father because he had made so many senior appointments while his father was still alive. So he, too, saw no need to take precipitous action against his colleagues. Equally important, no one may have been willing to challenge his rule for the same reason.

The newest despot, however, enjoyed no such advantages. His succession was rushed. He was surrounded by officials appointed by his father. The capital probably teemed with party apparatchiks, soldiers, security officials and family members who believed it was their turn to take control. It is far better in Pyongyang to be No. 1 than to be anywhere else in the hierarchy.

Kim probably has only a shaky grip on power, and knows it. He may hope to eliminate even the slightest hint of opposition, and if he cows his court sufficiently he might be able to moderate his approach accordingly. But the lesson offered by Joseph Stalin, who was at his bloodiest after taking complete control, does not suggest this is likely. And in the short-term, at least, Kim has made his regime even more unstable by changing Pyongyang’s political game so radically. If dozing off in a meeting means death, regicide makes some sense.

Still, the chief problem with North Korea for the rest of the world is not the “grotesque, grisly, horrendous public displays of executions on a whim and a fancy,” mentioned by Secretary of State John Kerry. Nor is it the breathtaking human rights violations against ordinary people.

No, the nature of the North Korean regime matters because it possesses advanced conventional military forces and a growing arsenal of missiles and weapons of mass destruction. It has chemical weapons and abundant missiles. It is working on longer-range missiles that could strike North America. While no one actually knows its nuclear capabilities in detail, recent estimates suggest it will have 20 warheads by next year and 50–100 by 2020. Analysts disagree about whether Pyonyang has miniaturized weapons so they can be mounted on missiles, and it almost certainly faked photos of a submarine missile launch. But that episode suggests a North Korean goal.

The Kim dynasty’s chief objective appears to be survival. Kim and company would doubtless be pleased to forcibly reunify the peninsula. but behind their rhetorical threats against America appears to be a realistic appreciation of U.S. power. South Korea, with twice the population of the north, can defend itself. It has far more advanced technology and greater international reach, having formed strong relationships with the north’s only potential allies, China and Russia. Probably neither would help Pyongyang if it started another war.

But even if a North Korean attack is unlikely, its nukes make this small, bankrupt and isolated dictatorship a problem, for they create opportunities for extortion against wealthy, fearful neighbors such as South Korea and Japan. Developing the ultimate weapon also rewards the military for its loyalty.

The north has never followed through on its threat to turn Seoul into a “lake of fire,” but it does commit lesser provocations. In 2010, it sank a South Korean ship and bombarded a South Korean island, but then backed off in the face of South Korean threats of retaliation. Kim Jong-un may lack his father’s sure touch about how far to go, but he has avoided any serious international missteps so far.

Despite fears that it would sell nuclear materials to terrorists, Pyongyang has made them available only to governments, and thus has not crossed what would surely be a red line triggering American action. Nothing suggests Pyongyang will take such a step, risking the new security that its nuclear advances brought it.

Simply put, the Kim dynasty is evil, but not remotely suicidal. They prefer their virgins in this world rather than the next.

What makes the north such a challenge is that there is no obvious solution to any aspect of its malignant behavior. There isn’t much that Washington and its allies, or even China, can do to keep it in check.

Current policy, combining isolation with an offer to negotiate if the north moves toward denuclearization, has failed. Pyongyang steadily built its nuclear arsenal and improved its missiles with international condemnation as background noise. It has proved more likely to behave provocatively when it thinks it was being ignored.

Some policymakers, such as Sen. John McCain, R‑Ariz., suggested war is an option. But even without nuclear weapons, the north could turn the south’s political, industrial and population heart into the threatened lake of fire. And Pyongyang is likely to see any military action as the start of full-scale war and an effort at regime change, prompting massive retaliation.

Decades of international sanctions have achieved little. North Koreans have suffered but the regime remains. It has made a virtue of isolation, calling it “Juche,” the philosophy of self-reliance. The new Kim appears to be reaching out more overseas, but the bulk of North Korea’s trade remains with China. Tightened controls would have little impact without Beijing’s backing. China can veto any United Nations measure with which it disagrees and so far has consistently undercut American proposals for tougher action. It remains Pyongyang’s economic lifeline.

The Obama administration has asked Beijing without success to press North Korea to be reasonable by cutting off food and energy supplies. China is unhappy with its unpredictable client but values stability over denuclearization, and is unwilling to make North Korean collapse more likely. It doesn’t want conflict on its doorstep with loose nukes and mass refugee flows. Nor does Beijing want to encourage Korean reunification that would put the peninsula under American control with U.S. troops on its border.

All this means negotiation is the only remaining option, not that it is possible to retain illusions of success. Virtually no one believes Pyongyang will give up its nukes. The benefits of keeping them are too great. Jong-un is unlikely to provoke his marginally loyal military by negotiating away their most powerful weapon.

But the north might be willing to agree to other U.S. objectives, such as a cap on nuclear activity, pull-back of conventional forces, greater international transparency or discussion on human rights. Beginning a dialogue, even initiating a diplomatic presence, however small, would at least offer the U.S. a window into an otherwise mysterious and closed society.

More importantly, the U.S. should turn South Korea’s defense over to Seoul. North Korea threatens America only because the U.S. has stations troops in the Korean peninsula. The need for such a presence disappeared years ago. South Korea developed a prosperous democracy, racing far past the north on almost every measure. Seoul has taken on an increasingly important international role. Its final step should be to take over the task of deterring the north. It’s a dirty job, but it should be the responsibility of South Koreans rather than Americans after all these years.

Washington would no longer be a scapegoat for North Korea, useful as a demon to inflame support for the regime. South Korea no longer would look to America as the lead in dealing with North Korea. China no longer could take advantage of the U.S. by demanding concessions from Washington to “help” by pushing Pyongyang into one set of international talks or another. Washington should still be interested in Northeast Asia and ready to cooperate with its friends.

North Korea’s communist monarchy could last decades longer.