I really don't think that the perspective of the North Korean government (such as is broadcast to the world) is very strongly grounded in reality.

For one thing, they've been saying the same thing since 1953. For another, it was NORTH Korea that invaded the South in 1950 (and an argument can be made that it was this invasion that ultimately made South Korea one of Asia's economic powerhouses), which resulted in UN action (and UN troops besides those of the US are in ROK today). The number of US military has decreased since 1969 from 56,000+ to roughly half that number today, while the ROK military has remained roughly stable (including 3.5 million in their "Homeland Defense Reserves").

I can't see how this is "Western imperialism."