The Arab Spring has gotten a generally favorable press in western countries—not surprising, since the governments attacked were undemocratic and, to varying degrees, oppressive, and democracy is very nearly the civic religion of modern developed states.
Like other religions, it relies as much on faith as on reason. African decolonization, carried out on a democratic model, repeatedly took the form of one man, one vote, once. Its results included some of the bloodiest conflicts of the postwar world. In several different countries, casualties were in at least the hundreds of thousands—worse, I think, than anything in colonial Africa since Leopold's Congo atrocities. That history should remind the supporters of democracy that it is a means, not an end, hence not always and everywhere an unambiguously good thing.
The recent success of Islamist parties, especially in Egypt, raises similar concerns. The final results might be governments worse than the ones that were overthrown—either democratic governments responding to majority opinion inconsistent with liberal values or a new and even worse generation of dictatorial rulers.
If that happens, it will be interesting to see the response in the U.S. and elsewhere.