One main reason the dollar is accepted around the world is that it is the currency of a country with a stable form of governance. A critical point is that it is a republic that guarantees rights including contractual and property rights. It is a representative democracy based on a two-party system that allows third parties which then get subsumed into one of the two big parties. Multiparty systems have proven far more unstable. Single party systems are far less transparent. There are other factors: a Fed somewhat insulated from political control, and a vibrant productive economy, in particular. But the positive role of the political system should not be dismissed.