Historians of revolutions are never sure as to when these great upheavals in human affairs begin. But the historians will not puzzle long over the Arab Revolution of 2011. They will know, with precision, when and where the political tsunami that shook the entrenched tyrannies first erupted. A young Tunisian vegetable seller, Mohamed Bouazizi, in the hardscrabble provincial town of Sidi Bouzid, set himself on fire after his cart was confiscated and a headstrong policewoman slapped him across the face in broad daylight. The Arab dictators had taken their people out of politics, they had erected and fortified a large Arab prison, reduced men and women to mere spectators of their own destiny, and the simple man in that forlorn Tunisian town called his fellow Arabs back into the political world.