Tbf, it's more like 'conservatives did conserve things back when they had spines'. The breed of conservatives who were willing to fill mass graves with progs kept most of Europe monarchic (in a genuine sense where the monarch actually wielded executive power) until WW1. Even in France, republicanism didn't stick until their defeat in the Franco-Prussian War of 1870-71, and they still almost became a monarchy in the early days of the Third Republic.

WW1, though...that was when, IMO, the rot irreversibly set in: it was where an entire generation of white Europeans steeped in a sense of romantic nationalism and tradition got decimated, the non-toothless continental monarchies were irreparably broken (including Russia, so called the 'Gendarme of Europe' for its role in containing & squishing liberal revolutions throughout the 19th century), the surviving European empires no longer had the wealth & power to indefinitely maintain control of their colonies, and staunchly modernistic ideologies like not just Communism and fascism but also liberal democracy itself filled the gap they left behind.

Tbf, it's more like 'conservatives did conserve things back when they had spines'. The breed of conservatives who were willing to fill mass graves with progs kept most of Europe monarchic (in a genuine sense where the monarch actually wielded executive power) until WW1. Even in France, republicanism didn't stick until their defeat in the Franco-Prussian War of 1870-71, and they still almost became a monarchy in the early days of the Third Republic.

That was when, IMO, the rot irreversibly set in: it was where an entire generation of white Europeans steeped in a sense of romantic nationalism and tradition got decimated, the non-toothless continental monarchies were irreparably broken (including Russia, so called the 'Gendarme of Europe' for its role in containing & squishing liberal revolutions throughout the 19th century), the surviving European empires no longer had the wealth & power to indefinitely maintain control of their colonies, and staunchly modernistic ideologies like not just Communism and fascism but also liberal democracy itself filled the gap they left behind.