[O]ne's political ideology is inextricable from one's view of history. - Brian Reynolds Myers

North Korea's future depends on a large extent on South Korea's future.

[I]t was the Yankees and not Korean “reds” – a tiny force even in their 1920s heyday — whom the Japanese authorities were most intent on infamizing. After Hirohito’s surrender all the main tropes went straight into the agitprop of the South Korean left. Thus did the Workers’ Party vilify Yankees as “bloodsuckers” when agitating Jeju islanders, who had been subjected to especially intense Japanese propaganda during the war.

The U.S. was never stronger, North Korea never weaker than in 1994, yet even then the fear of an artillery attack on Seoul prevented an air-strike on Yongbyeon. You can put it another way and say that the very success of the nuclear program, the fact that it has gone this far, proves that it was never necessary for North Korea's security in the first place.