A short explanation from Australia's Lowy Institute; better than a long WaPo piece today:http://www.lowyinterpreter.org/post/...CC=3218904964&

How can we explain such an outcome? A number of characteristics make this small country, with modest natural resources, a special case in the Arab world:
  • The role played by civil society in highly urbanised areas.
  • A modernised society thanks to the abolition of tribal structures after independence in 1956. Tunisia is today a country unified by its municipal organisation.
  • Tunisia is relatively homogeneous and unified, with no strong ethnic or religious minorities. This is the why the country is open to modernity (female emancipation, social reform, multi-lingualism, some religious tolerance) without risk to its national unity.
  • A republican army with no political ambition.
  • A relatively advanced political and social life (eg. political parties have existed since the 1920s, and Tunisia has the oldest trade union in Africa).
  • Modern education and high literacy.

What's more, Islamist fundamentalists played no role in the revolution, the army did not intervene against the popular revolt, and Tunisian women played a key role in defending civil liberties during the uprising.