It sounds like a doomsday scenario drawn up by strategists at the height of the Cold War. … Chinese armies move south into the Korean peninsula and collide with American and South Korean forces moving north. The resulting clashes spark war between nuclear-armed superpowers. … A new report says such a confrontation is still a real danger in the event of a sudden collapse of the North Korean regime. … The report produced by the US research institute, the Rand Corporation, says that North Korea is a failing state that could fall apart at any moment. … It says agreement is urgently needed between Washington and Beijing on contingency plans - including setting up a temporary line of division inside North Korea to keep their armies apart. … Analysts have been predicting the imminent collapse of North Korea for the last two decades.