Recent presidents have gone off on ad hoc adventures. They have set unattainable goal because they have framed the issue incorrectly, as they believed their own rhetoric.

What is the great fear of the United States? That an Eastern power will build a navy to challenge us. How do you keep them from doing that? Keep them at each other's throats so they don't have any money to do this. This is why we fought the First World War, the Second World War, and the Cold War.

Constraint theory argues a number of things. First, that the impossible has to be identified. Second, that the actor is then constrained by circumstances to act a certain way. For example, should we invade ISIS? Can we invade ISIS? What would it take to invade ISIS? Once you ask that question you discover the price of that option and then you take a look at American politics and see that the country is probably not prepared to invest the 2 to 3 million people that it would take to defeat ISIS and the insurgency afterwards. All right, so that's not going to happen.

When I went to war, I did not go making geopolitical calculations. I went to war with a lust.

If you go through the list of things that are not possible you're left with a very finite amount of possibilities. The fancy name for this is constraint theory. It's a nonquantitative model, but it's a field of mathematics.

There is no difference in a country between military, economic, and political affairs. It's useful for Business Insider to divide things that way. That's useful for a college program. But a country is a country. How do you understand China's economy without China's army? If you take these all into account you're ready to explain a question like, "How come the US doesn't have a debt problem?"

Now if you can recognize and memorize a grandmaster's game, and you have the respect to understand [Zimbabwean president Robert] Mugabe who has survived past anyone's expectations, and make the simple assumption it wasn't an accident, and you understand why he did what he did, now you're ready to predict ... The key to forecasting is to understand both the constraints nations are under and the manner in which the struggle for power shapes leaders.