Kim Il Sung was a Stalinist, and had received his principle support from the Soviets before the UN Army pushed so close to the Yalu River, at which time China decided to intervene. His negotiating style was much like Stalin's but also a much more blunt object. While i was stationed in Korea, a North Korean work party severely beat an American MP. (A Swiss officer who was just leaving threw him in his jeep and drove him to our hospital--the man was severely beaten but not permanently injured.) It was part and parcel of their "negotiating style." It was saying, in so many words, "see how tough and uncompromising we are?" No one had any illusions about the nature of the incident--those workers would not have behaved as they did without being prompted to it by authority. The Americans reacted by doubling the guard, and replacing the American MPs with ROK combat MPs. That sent a message to the North Koreans that if they wanted to try that again, they could play with creating an incident which might lead to war, given that ROK combat MPs would respond to such an incident by beating those workers to death. (Combat MPs are arguably the toughest troops in any army. The U.S. Army's 728 Military Police battalion, a combat MP battalion, was wiped out three times during the Korean War because they cover the retreat of higher headquarters, and they won't retreat as long as there is any possibility of that higher headquarters being overrun--they protected UN and Eighth Army headquarters.)
You see this kind of thing with the Persians, too--but they're pikers compared to Joe Ching. Perhaps you will recall that prior to the flap about their nuclear program, they had proposed that petroleum be priced in euros rather than in dollars. That was something which would seriously alarm the energy industry in the United States, and i personally believe that the Bush administration responded to that with brinksmanship, bringing up the Persian nuclear program, and darkly hinting of invasion. An invasion would have been the height of idiocy, but i suspect their brinksmanship was effective to the extent that Iran was not prepared for that response, and that they have been dismayed since then dealing with it. They won't show it, of course, and they talk tough--but they've dropped their effort to get petroleum priced in euros.
The North Koreans overreach themselves constantly, though, with their bellicose position and their threats. It's hard to take them seriously, because sparking a nuclear conflagration would seriously interfere with Kim Jong Il's surfing for internet porn. I suspect that international diplomats know how to deal with this, and it in fact serves to provide leverage to get the Chinese to put more pressure on them.
The losers in all of this are, of course, the people of North Korea. They're still starving, and that isn't likely to change any time soon.