It reminds me of the rivalry between Greece and the Roman Empire; Greek democracy did finally prove its superiority, even when ancient Greece no longer existed.

A mighty strange account of history. Greek democracy ended in stupendous disaster with its outstandingly incompetent Sicilian Expedition (aggressive invasion) resulting in the entire Athenian army and navy being destroyed. (Parallels with the present?) That happened while Rome was in early stages of its Republic. This only became the empire over 300 years later.
Democracy was generally recognised as a failed system till only a few hundred years ago when the Brits started enthusing about it.

Oldcommie--Socialism has not been tried because in your concept it can't be. The USSR certainly had a planned economy and highly socialised values and culture. Neither big socialism nor big capitalism work. The left-right preoccupation misses the point that nothing big anonymous works, only small non-anonymous local community can.