There's one explosive factor that sets Egypt apart from Saudi Arabia, Tunisia and every other country in the Middle East.

Egypt has nearly 5,300 people per square mile.

The closest competitor (not counting city states like Hong Kong) is Bangladesh, with 2,900 people per square mile. Tunisia has less than 200 people per square mile.

We're getting that alarming figure for Egypt by disregarding the uninhabitable desert that makes up 96 percent of the country. Nearly everyone in the country lives in a 15,000 square miles of arable land around the Nile Delta. Even with a similar calculation for countries like Tunisia, no other country comes close. (You can see a partial list here).

Population density contributes to poor health and social unrest. It means the riots become very large and hard to stop. And the flip side is a lack of arable land, which means Egypt is especially vulnerable to a food crisis.

Add this to demographic factors like high population growth and you've got a problem that won't be fixed soon.