The case of Raymond Davis in Pakistan illustrates one of many new problems that accompany an era of more widespread democracy. Mr. Davis is a US diplomat who killed two Pakistanis during an incident at a traffic stop in the Pakistani city of Lahore. No matter what the circumstances of the case, international law gives him diplomatic immunity.

Unless it is not playing by the rules (see Iran's seizing of US diplomats in 1979), a government abides by a tricky concept like diplomatic immunity, which protects envoys from becoming pawns in international disputes. In the old world of autocratic regimes, the public may have grumbled, but its opinion didn't matter.

Shift to democracy, as Pakistan did in 2008, and populist voices are raised: What right does an American have to kill two Pakistanis and escape prosecution, they ask. A shaky government such as Pakistan's can come under enormous political pressure as a result.

The new world of democracy emerging across the planet will bring many such misunderstandings. It may take years for newly empowered people to learn for themselves the reason for a concept such as diplomatic immunity.