Could war again leave its bloody mark on the Korean Peninsula? Judging from an unusual rhetorical shift by North Korean leader Kim Jong Un, some longtime observers believe he may be disillusioned with diplomacy and is girding for conflict.

Though the two Koreas have remained technically at war since the Korean War ended in just an armistice in 1953, Kim has in recent weeks labeled the South his nation’s “principal enemy” while abolishing agencies focused on reunification and threatening to enshrine in the North’s constitution a goal of “completely occupying, subjugating and reclaiming” its southern neighbor.

The North Korean strongman has also signaled that his regime no longer recognizes the two Koreas' de facto maritime border, the so-called Northern Limit Line, even staging days of live-fire artillery drills in the area that prompted the evacuation of residents of one nearby island.