North Korea is indirectly fed by all its neighbors, because its demise will mean a huge influx of refugees, very poor and largely not adapted to life in a non-North-Korean society. It will also mean that South Korea would have to absorb and restore North Korean territories; even mighty West Germany had visible difficulties absorbing East Germany, which was pretty prosperous by the Soviet bloc measures.
I don't think the US or Europe would feed starving USSR to prevent it from collapsing.
Also, North Korea is pretty compact. Keeping a country the size of USSR in an iron fist would be somewhat harder (though this has been done in 1930-50s), and attempts to cut certain regions away from an ailing empire would probably be much more successful.
China feeds North Korea. I think the primary purpose of DPRK's existence is internal politics of its large neighbour and supporter. DPRK is there because China keeps it up and running as an isolated laboratory of stalinist communism, to remind left-wing traditionalists inside Chinese Communist Party about what their version of communism produces for the people.
I don't think the US or Europe would feed starving USSR to prevent it from collapsing.
Also, North Korea is pretty compact. Keeping a country the size of USSR in an iron fist would be somewhat harder (though this has been done in 1930-50s), and attempts to cut certain regions away from an ailing empire would probably be much more successful.