Why is the US considered to be the police officers of the world?

Becuase, after world war 2 there was only two countries that could focus on there military, the US and Soviet Union, and both had most imput on the UN when it was started. Then the US and Soviet Union had different views on how to run there country and then fought with each other when communism started spreading, the cold war. The Soviet Union fell and the US was now the supper power of the world, with China rising behind it. Then the US became dependent on other countries for its resources the people need and now we just go out and protect "our friends and allies", but were really just trying to protect what the government needs to keep our economy running.

In short, the US just go out and claim its fighting to protect us but were just using it to get more resources.