Democracy works. Authoritarianism works too.

Athens, the Ancient version, had become the dominant power of the Ancient Greece as a democracy. Only the Parthenon was build under Pericle’s rule. And Pericle was, for all intents and purposes, a dictator.
Rome, the Ancient version, had build a huge empire. As a democracy. Then enlarged it some more. As a growingly authoritarian and eventually discretionary regime.

England had started as the most democratic kingdom in Europe. Building upon the democratic traditions developed by the Vikings, the barons had forced King John to sign Magna Charta Libertatum. Way back in 1215.
Meanwhile, France – England’s neighbor and long time competitor, had become the dominant power in Medieval Europe. As an increasingly absolutist monarchy.

At some point, the people living in the future United States of America had decided that they had enough. That they wanted to enjoy the same privilege as their British counterparts. “No taxation without representation”.  George III would have no such a thing so the US had been established as the first democratic modern state. And the most successful to date. By almost every measure.
Following on America’s foot steps, the French had their Revolution. After a very short – and very tumultuous, democratic stint, they had reverted to authoritarianism. And conquered almost all Europe, under the command of Napoleon Bonaparte the First. Only to be eventually defeated by a coalition led by the more democratic British empire.

On the other side of Eur-Asia, things had been more linear.

The Russian Empire was developed in fits and starts. When the dictating ruler knew what he was doing – Peter the Great, for instance, things went forward. When not…
India had been, for all but the last 70 years or so, a melting pot of feuding dictatorships. Yet had developed a fascinating culture and much of what we currently call science and technology. The numbers our computers crunch had been invented there. And the steel we use to build our cars
The Chinese Middle Kingdom had once been the most civilized country on Earth. Then had crumbled under the assault of the marauding already democratic Europeans… only to revive, like the famous Phoenix… and all these while remaining submissive to a succession of authoritarian regimes.
Japan is a story by herself. Never fully authoritarian and yet still ‘imperative’ in many ways even today, she had somehow managed to put up a relatively good show. But for the period when she had succumbed to the ‘charms’ of hard core dictatorship, of course.

Coming back to Europe, I have to note that in the last century the inevitable tension between democracy and authoritarianism has produced immense tragedy.
WWI was the consequence of the inflexibility inherent to the authoritarian regimes. The leaders of the Keiserlich und Koniglich Habsburgic Empire, the Deutches Reich and the Russian Empire were not able to solve their disputes otherwise than dragging the whole continent into a huge mess.
Which, unsolved, had given birth to a second, and more horrible, one.
To complicate things even more, the battle was not fraught between the democratic regimes and the authoritarians.