Well, the cold war was much more severe. I meant to ask "Could this last 50 years, involve many proxy battles and grow to a cold-war-scale political tension?".
As to proxy battles, NK is not a super power like the Soviets were. They can't fight proxy wars. But they can shell ROK islands, sunk ROK ships, make threats, stage provocations across the DMZ, all of which they've done before.
I'm not so sure we can call much of anything much of a battle since the armistice, though there have been numerous accusations of violating the agreement and there have been some deaths since the armistice agreement.