First of all, the chance of anything actually happening here are slim to none.
You never know, but both countries have everything to loose from actual armed conflict, so expect tons of heavy rhetoric and little else.
If not, a lot of people are severely screwed....
Anyway, Asiana policy is like any other airline. If it is YOU that get cold feet and want to cancel, the refund policy depends on your booking class.
Most Asiana tickets are refundable for a fee, except heavily discounted tickets that are seldom sold outside Korea.
Now if something actually does happen, I am sure they would claim Force Majeure, but instead of you loosing your ticket, they would likely give you the option of postponing your journey or getting a refund, much in the same way airlines settled the Icelandic Ashcloud mess a month ago.
Of course, this is the norm, but it all depends on what actually happens and the severity of it.
But you shouldn't give too much thought to this methinks