I think I understand where Eco's coming from, although I'm closer to what Madlib believes about what 'authoritarianism' really means.
Correct me if I'm wrong, but Eco believes that one can use authoritarian means to impose ideas of western-style liberal democracy on a conservative/fundamentalist/dictatorial régime and that the fruits of that change will seep into the political culture, initially by force and later by consent. How'm I doing?
Gardener's point about Ataturkist Turkey is relevant in that Mustafa Kemal thought along those lines. The idea that liberal democracy is something to aspire to, to educate the populace about and to eventually achieve is not necessarily something that happens overnight. Atatürk was perhaps the most reluctant dictator the world's ever seen; he never saw his dictatorship as anything other than a transitional phase towards democracy.
Atatürk, while being nothing remotely like a Marxist, did coincide with Lenin and Trotsky in seeing the necessity of going through a phase of political transition; him via a dictatorship, them by a proletarian vanguard, the 'dictatorship of the proletariat'.
The problem was, and is, that the transition never takes place, not in those would-be communist states, not in Atatürkist Turkey, and not in those US puppet dictatorships, of which there have been many. South Vietnam, Pinochet's Chile, Saudi Arabia, Karzai's Afghanistan or post-war Iraq, none of these countries where the US has had high hopes of implanting liberal democracy have seen that system take hold. Is it the implementation that's at fault or the very concept of imposing an alien system on a political culture for which it isn't appropriate?