Those questions become particularly important during crises in the isolated country's relations with the outside world. Pyongyang last week triggered the latest such crisis by announcing that it possessed nuclear weapons and would not return to talks on the issue with Washington, Beijing, Seoul, Tokyo and Moscow.
Outsiders have debated the sanity and rationality of rank-and-file North Koreans since it became apparent the father-son team of Kim Il Sung and Kim Jong Il had brainwashed pretty much the entire population.
During my first visit to North Korea, in 1979, people robotically spouted memorized slogans in response to my questions. Many also showed the gentleness that Americans were accustomed to seeing displayed by members of true-believer groups. I couldn't help finding parallels to the Rev. Jim Jones' Peoples Temple cult, nearly 1,000 of whose members committed mass suicide at Jonestown, Guyana, in 1978.
In March 1993, during the first nuclear weapons crisis, Kim Jong Il placed the country on a "semi-war" footing and held a rally in Pyongyang. Soldiers had shaved their heads to prepare for war. Sobbing, they sang: "Even though the world is overturned 100 times, still the people believe in Marshal Kim Jong Il."
One of those soldiers defected later to South Korea. He said North Koreans all believed that if war broke out with the United States and South Korea, "everyone would die - North and South." Nevertheless, he said - repeating what I was hearing from other defectors - the people actively wanted to go to war and get it over with. They felt they had nothing to lose. "It's either die of starvation or die in war."
Popular hysteria peaked during the 1990s and probably has diminished somewhat. North Koreans who did not die as a result of food shortages focused their attentions on newfound survival strategies, such as trading and entrepreneurship. Still, there has been no letup in the incessant indoctrination that teaches people to blame their problems not on their rulers but on the U.S., Japan and South Korea.
To the extent that the world's most effective propaganda continues to produce fanatical obedience among young people, the North Korean population - especially the military, more than 1 million strong - remains a cocked weapon. If the people ever respond to an order from on high and march off to fight to their deaths, the result would probably be among the bloodiest wars in history.
The key question, then, concerns the leader who has his finger on the trigger: Is Kim Jong Il a madman?
I'm no doctor, but my short answer, based on having studied him for many years, is no. Though Kim is a despot, callous and sometimes brutal, he is not a genocidal maniac in the Hitler mold.
Kim makes rational decisions to maintain his power. In 1993, famine forced his subjects to break many laws in order to survive. Instead of cracking down, he instructed security officials to be lenient and "avoid making internal enemies." Perhaps with that single stroke he reversed a process that could have led to popular uprisings and regime collapse.
There does remain a lot of weirdness to explain. Kim was spoiled rotten as the ruler's eldest son, and some of his publicized behavior as an adult has been bizarre in the extreme. For example, he had a famous South Korean movie director and the director's actress wife kidnapped so that he could enlist them in a project to improve North Korean cinema.
One bit of North Korean army lore has it that Kim, during the first nuclear crisis, vowed to his father that rather than lose a war he would "destroy the world." The suggestion is that he might be just crazy enough to bring on nuclear Armageddon.
The counterargument is that disseminating such a scary image is intended to buck up his subjects' fighting spirit while persuading his enemies to appease him. In this argument Kim is crazy - like a fox.
It does seem likely that Pyongyang intends its development and advertisement of nuclear weapons capability to deter would-be attackers.
Kim is playing for high stakes. Clearly, he fears not just for the future of his regime but for his own life. Newsweek has quoted an unnamed visitor from abroad who says Kim laments that North Korean conventional forces are outmoded and inadequate. Without nuclear weapons, the current Great Leader believes, he would be personally targeted.
Call that paranoia, but it's rational enough, considering how many people in high places in Washington would dearly love to see him dead.