The way I think of it is that democracy is a very expensive form of governance. Having legal protections and representation for all members of society is great,

The way I think of it is that democracy is a very expensive form of governance. Having legal protections and representation for all members of society is great, but it is also a luxury that allows various bad actors and interest groups to clog up the entire system for their personal gain. And the only way to afford this political luxury is to ensure that the economic vibrancy of an open system produces enough wealth to patch up what gets bled away by democracy's inherent costs. And if that is not enough, to have an external source of wealth to subsidize this continuous bleeding. Because if democracy fails to produce enough wealth and distribute it to enough people, then people quickly turn to authoritarians who claim they have all the answers. Under these assumptions, the burgeoning of democracies in the 1990s might be due to indirect economic subsidies from the US. And the reason why the US could be a democracy is because the American continent, with other resource claimants eliminated by disease and war, could generate enough wealth to subsidize a messy but democratic system of governance that otherwise might have been overrun by more powerful authoritarian neighbors if it had been born on the Eurasian continent.