Well I imagine that East Asia would be more of a Cold War hotspot instead of the major non-aligned bloc it was IOTL. With greater Cold War tensions I imagine that Japan would aim to align themselves more towards the US, which could butterfly away demilitarisation, especially if there was a major conflict just across the sea from them. Without a strong bloc of non-aligned countries China might not pursue such a radical split with the Soviets and built ties with their neighbours.
Of course if Korea is divided then there is a good chance that outright war could break out, which means a good chance of nuclear war breaking out, so I guess everyone would die.