I'm not an Iran expert.

To understand why dictators fall, it helps to recognise factors that produce a perfect anti-dictatorial storm. Barring missteps such as those that led to Gaddafi's undoing, a dictator's survival can be at risk because of newness in office, poor health, or old age combined with economic trouble.

I'm not engaged in predicting random number generators. I actually get phone calls from people who want to know what lottery numbers are going to win. I don't have a clue.

Dictators, unlike Democrats, depend on a small coterie to sustain their power. These backers, generally drawn from the military, the senior civil service, and family or clan members, have a synergistic relationship with their dictator. The dictator delivers opportunities for them to become rich, and they protect him from being overthrown.

If you're running a dictatorship, you don't really have to worry about the welfare or the property rights of the ordinary citizen. Only the people who keep you in power, a very small group, matter.

There are lots of people shaping decisions, and so if we want to predict correctly, we have to pay attention to everybody who is trying to shape the outcome, not just the people at the pinnacle of the decision-making pyramid.