Hate and revenge

Tyler Cowen writes:

CONSISTENCY TEST? Today's New York Times tells us that the bombing in Iraq, which killed a moderate Shiite leader, "dealt a blow to American efforts to establish order..." Other papers have said pretty much the same. But when the United States, or Israel, kills terrorist leaders, are we not told that dozens will rise to take their place, making the movement stronger than ever?

Yes. And the reason why is because there is a fairly obvious link between hate and revenge and becoming a terrorist. But its not so obvious that hate or revenge motivates people towards respecting democratic elections...