The economical and political power of the US is the reason for that. And the military might is what backs up the political power. The same pattern repeats its

The economical and political power of the US is the reason for that. And the military might is what backs up the political power. The same pattern repeats itself in history: those with the biggest army popularize their culture, language and coin. The Roman Empire is a good example. See https://en.wikipedia.org/wiki/Hegemony https://en.wikipedia.org/wiki/Hegemony