Diplomatic Immunity

I don't get it. Can someone explain it to me? WHY!?! do we give diplomatic immunity? Why do we allow certain people the right to be above the law?

According to the State Department:

International law requires that law enforcement authorities of the United States extend certain privileges and immunities to members of foreign diplomatic missions and consular posts. The purpose of these privileges and immunities is not to benefit individuals but to ensure the efficient and effective performance of their official missions on behalf of their governments. Most of these privileges and immunities are not absolute, and law enforcement officers retain their fundamental responsibility to protect and police the orderly conduct of persons in the United States.

Here are the "legal aspects of diplomatic immunity" as found on the U.S. Department of State's website. (Can't read it? Click on the link above and it'll take you to this chart.)

Most of these privileges and immunities are not absolute, and law enforcement officers retain their fundamental responsibility to protect and police the orderly conduct of persons in the United States.

And yet, if you look at the chart, it seems that law enforcement has their hands tied in that they are unable to detain or arrest many officials. And how does this ensure efficient and effective performance?

I JUST DON'T GET IT.