So far, the dictators' survival guide seems to imply that staying in power is not so difficult. Monitor and control the population, pay off a small number of influential people and use elections to demonstrate their power. And to some extent that's true. Once dictators have ruled for a few years and mastered these levers of power they become very difficult to dislodge.

Since 1960 in Africa, more than a third of African presidents who lost power were either jailed, exiled or killed.

Moreover, there are very strong disincentives for dictators to choose to stand down, as Brian Klass points out:

"Dictators face real risks to retirement. Since 1960 in Africa, more than a third of African presidents who lost power were either jailed, exiled or killed. Losing power will open up an entirely unpredictable situation in which their rivals will be able to enact revenge."

In general, most dictators cling on to the bitter end. And who wouldn't, given some of those possible alternatives? This means that any survival guide for dictators should have a chapter that advocates a good diet and plenty of exercise. Why? Because according to Bruce Bueno de Mesquita, there is one particular set of circumstances in which that carefully constructed set of loyalties within the government is likely to collapse:

"The problem that any dictator has in staying in power if they have been there a very long time, is that they either are believed to have a terminal illness, or they have the terminal illness that we all have - they are very old."

This, he argues, is exactly what happened in Zimbabwe:

"Mugabe's problem in Zimbabwe was being in his 90s. Eventually people understood that they couldn’t count on him to keep paying them in the future. And they saw that he was lining up his wife to be his successor, and of course they wanted to be the successor."

Until senility or illness claims them, we should not underestimate dictators' drive to cling on to power. And it's that fight for survival which explains why dictators behave the way they do. It's also that fight that defines, and often destroys, the lives of the people they rule.