Our laws try to keep us in a limit and teach us to be equal and fair in order to earn certain freedoms or privileges. Our laws keep men and women equal while many other countries don't. Also we don't have discrimination, these are all positive laws so they aren't exactly abusing human rights.
It's tempting to say that banana republics run by dictators have no real laws and therefore the US should impose our values for their own good... Until you look at the practical results. Ever since the dawn of the 20th century, the US has behaved like a typical empire, intervening -always in the name of freedom and justice- in every country where there was an economic incentive to do so. However, countries where there was nothing to be gained were either ignored or even worse, we were the main supporters of their own dictators. Some very smart and capable people is already working on the concept of international courts, and while the practical results so far are very thin when not meaningless, that's the way to go. The US alone can only act in its own interest -and there's no strong reason our interest has to be aligned with those of the oppresed peoples of Earth.