More democracy, more power for a nation, i.e. USA. On the other hand, democracy can be applied everywhere, even a chaotic, corrupted India can has taste of it (although 40% of its population are illiterate and a quarter of its congressmen faced criminal investigation). Does democracy make a nation more powerful? Or it's just a camouflage fooling people around?
It depends. It depends on too many different factors. It works in some places, and in other places it has more or less failed all together. You can't really compare USA (innovative) success with it to any other nations, because each nation is unique within it's own population and history (different zeitgeist). Some nations and countries have been at their strongest periods (militarily, economic, and even socially) with ruthless dictatorships/tyrannical conquerors and unbending totalitarian governments (aka police states). American (republican) democracy is unique in its own way, like Athenian (classical) democracy. You have more (soft) social democracy in Europe, while the other type of social democracy lies in south Asian countries whose self-proposed democracy status (or the people's republic) is very questionable.
A democracy is when two wolves and a sheep take a majority vote on what’s for supper, while in a constitutional republic, the wolves are forbidden on voting on what’s for supper and the sheep are well armed. Hitler came to power in a democracy.
But, my main point should've been there are many types of different democracies. http://en.wikipedia.org/wiki/List_of_types_of_democracy
IMO, Democracy is rule by the people for the people. That's why you can't transplant democracy, it has to come from within, from the people. When the powerful get control they never want to let it go, protecting status quota.