A lot of countries that converted to democracy did this because their populations looked up to US and wanted to have better lief.
You also put pressure on other countries when they claim are democratic but fail to do this in practice (which is the case of Belarus or Poland where I live).
US does this actively and frequently in many forms, by voicing "concerns" or putting embargoes on countries that break their own rules.
Obviously, that pressure is much less effective when you do same things you try to pressure other countries to not do.
Case in point, a system that does not care about rights of their inhabitants is usually much more effective at running large scale projects. For example, China just deciding to shut down everybody in their houses in Wuhan and shoot if you don't comply. And just like that they got their pandemic under control.
> One of the reasons strongmen rise to power in third world countries is as a reaction to imperialism
No, they rise because they can.
And not just in third world countries. Germany was definitely not a third world country when it allowed Hitler to rise and start a global war. What about Putin?
We see these guys mostly in third world countries now mainly because without democracy it is difficult to keep up with democracies without some special situation (like Saudi Arabia being gifted with huge oil reserves).
In non-democracies normal people have trouble preserving their wealth over long periods of time. You need to be "in favours" of the ruling entity to be wealthy and the wealth vanishes if you fall out of it.
Democracies are on the other hand, by definition, people ruling themselves, and this should in theory mean a lot of focus is on personal security and freedom. This should mean it is safer to conduct business over long periods of time, accumulate wealth and generally contribute to GDP.
I am the first one to be vocal of US imperialism, but you can't deny that it is US influence that caused several modern countries to be democratic.
But I feel after the 1960's the US has slowly lost that ideal, and the visionary leaders (Woodrow Wilson, Roosevelt or Eisenhower) are no longer anywhere to be found (whether the electorate don't tolerate or desire them I'm not sure).
Both the Japanese and Korean antidemocratic moves took place in that pre 1960 era for example.