LONDON — The revolution in Tunisia was set off by the self-immolation of a poor vendor persecuted by an autocratic and corrupt regime. The consequent toppling of the Tunisian dictator inspired revolts in Egypt, Bahrain and Libya and led to unrest in the Yemen, Algeria and Jordan. It also spurred the opposition in Iran. The ousting of President Hosni Mubarak of Egypt as a result of popular pressure was achieved because the Egyptian Army refused to slaughter Egyptian civilians. In Libya, Col. Moammar Gadhafi is trying to suppress dissent by brutal terror. In Bahrain the opposition has won concessions from the rulers.

It is too early to predict the final outcome in the Middle East and we need to be wary of too much wishful thinking about an "Arabian spring" and the spread of democracy throughout the region. The toppling of tyrants who have salted away the riches of their countries in personal bank accounts is welcome and the development of democratic institutions most desirable. But it will inevitably take time for radical changes to be implemented and there may well be steps back as well as forward in the process. The countries in which revolts have taken place are all different and there is no single unifying force or ideology behind the revolutions.

The absence of a democratic tradition is often cited as a reason for caution, but this did not prevent most East European communist regimes from developing democratic institutions and legal systems. Many did so quickly and sufficiently to enable their countries to become members of the European Union, which insists that all members adhere to democratic principles. There are important cultural and religious differences between Eastern Europe and the Middle East, but it would be wrong to argue from this that Arab countries are incapable of becoming democracies.