While revisionist historians suggest that the United States instigated the Korean "War," the Democratic People's Republic of Korea (North Korea) has a long and unprecedented history of belligerence and arrogance toward the Western world, and specifically the U.S. That being said, without the continued foreign aid of food that the DPRK receives from the U.S. and other Western nations, the situation of the people of North Korea might well have deteriorated into the eradication of their civilization through starvation.
With a standing force of 1.1 million active-duty soldiers, the DPRK has the fourth-largest military in the world, comprising up to 20% of its male population. With an additional reserve of 7.7 million civilians, North Korea is the most militarized nation in the world (considering they have a total population of 25 million). This force is viewed as a significant threat, their antiquated equipment notwithstanding, due to the sheer numbers that the DPRK can field, and their proximity to significant South Korean civilian populations. Additionally, North Korea's numerous artillery installations, aimed almost exclusively at South Korean civilian targets, is intended to be a significant deterrent to another armed conflict.
However, the DPRK has faced dire economic situations, arising both from its over-emphasis on military spending (take note, Washington!) and its horribly backward, largely agrarian society. This resulted in the deaths of over 1.5 million Koreans in a terrible famine in the 1990s, and the effects of the famine still linger through anemia and malnourishment (North Korea still has a long way to go if they want to rival the greatest mass-exterminator in history; the Kims would need to starve every North Korean to death four times to beat Chairman Mao's record of mass murder).
Considering how backward the DPRK is, their woefully outdated agrarian economy, and their continued belligerence toward Western powers, it would appear that the only reason they have any legitimacy whatsoever in world politics is that the very same Western powers they bluster against continually legitimize them through diplomatic avenues and foreign aid (without which, many more North Koreans would likely starve), and their presumed nuclear capacity (no thanks to Japan). The question then, is, why do we continue to prop up the DPRK in spite of their continual aggression toward the U.S. and our allies?
While non-intervention is something that the U.S. isn't very familiar with, perhaps the State Department could entertain a change in policy toward North Korea: just ignore them. When foodstuffs and other aid stop coming in from the Western powers the DPRK continually vilifies, perhaps Kim Jung Un and the military leaders would be willing to tone down the rhetoric. After all, an empty stomach, while tragic (since the peasants will starve long before their leaders' opulent lifestyles are affected), is a significant bargaining chip. Why should we, the American taxpayers, be forced to send rice and money to a totalitarian state that simply uses our donations to support its propaganda campaign and military buildup?