That's funny. Everything I have ever read shows that democracy can not be imposed from outside. In all cases where democracy flourishes a pre-existing condition for its truimph existed. The USA has never been able to impose a democracy on a nation that did not have the foundations for a democracy and the USA has never been able to create anywhere-anytime the foundations that would allow for a democracy to evolve.
That doesn't stop us from trying. Over and over.
Of course, one definition of insanity is doing the same thing again and again and expecting a different result.
Mmmm. Yes. Like Hirohito's Japan? Or Hitler's Germany?
Except for feudalism until the mid 19th Century, Imperial despotism until the early 20th Century and military despotism until August, 1945, what foundation did the Empire of Japan have for a democracy in August 1945?
Except for the disaster of the Weimar Republic, what foundation did the Third Reich have for a democracy in April 1945?
Winning a war and then immediately going home allows the defeated enemy to simply re-group and re-arm so that you can have the fun of fighting the sequel to the same war all over again 10 or 20 years down the road.
The fact that, after millenia of warfare and bloodshed, both Japan and Western Europe are currently holier-than-thou pacifists is due to the fact that the U.S. stayed around after 1945 to establish the Pax Americana.
Such was not the case after 1918.
As a result, 40 million Europeans and over 400,000 Americans died between 1939 and 1945.
Even in cases where the population of the defeated country is as unsuited to democracy as gasoline is to an open flame, it behooves you to stay until the autocratic regime that emerges is in your camp and not in the camp of your mortal enemies.
Unless a nation is fighting wars merely for practice or for martial glory, it unwise to "bug out" and immediately abadon the fruits of your victory to the very enemy you have just defeated.
Your statement is false. Postwar Japan and Germany are but two examples that disprove your statement. Certainly Japan, which had no concept of democracy in its entire history has proved to be an excellent example of that fact that imposing democracy can work. In addition, I would submit that Japan's democracy is indeed evolving given its recent amendment to its constitution allowing posting of Japanese troops to other countries.
With regard to Germany, while the concept of voting was not foreign, the release of the German people from the grip of a totalitarian regime so that they could re-establish a participatory democracy was striking - to say the least.
While it may seem trite to say something like "America is a democracy builder", the fact is that we have been such for a number of countries. As with all things humans do the outcomes have not all been perfect. However, to impugn that we as a nation are hegemonic simply because we have not been totally successful in all our endeavors is patently absurd.