For those who see North Korean leader Kim Jong-il as a dangerous lunatic prepared to risk the annihilation of his regime by launching a devastating attack on his neighbors, there is no shortage of supporting evidence.
But for analysts and policymakers trying to gauge the chance of a catastrophic war, game theory offers a crucial insight. In Kim's position, it is perfectly sane to seem mad. And it would be a disaster for him if the world believed he was rational.
"No fool stays in power for years ... when there are so many generals, sons and wives waiting in the wings to launch a coup," says Bruce Bueno de Mesquita, who specializes in political forecasting based on game theory, and who advised the U.S. Defense Department on Korea in 2004.
For years, Kim has veered unpredictably between belligerence and conciliation. Viewed in terms of game theory, this behavior is entirely rational. In fact, it is Kim's only viable strategy.