Jonathan Cristol is a fellow at the World Policy Institute and a senior fellow at the Center for Civic Engagement at Bard College. You can follow him @jonathancristol. The views expressed in this commentary are his own.

(CNN) Kim Jong Un is not crazy. Kim Jong Un is not irrational. He's probably not stupid either.

We Americans frequently make the mistake of assuming that our enemies are crazy, irrational or stupid. We expect every other nation state to go along happily with what we want it to do. When a world leader does otherwise, we attribute our lack of understanding to some flaw in that person's judgment.

Not all political systems mirror the United States; not all cultures are our culture; and not everyone's interests are America's interests.

We underestimate our enemies at our own peril, and the very real threat posed by Kim Jong Un in North Korea is no different.

Is it true that Kim executed his own security officials by having them shot with an anti-aircraft gun? South Korea certainly thinks so.