LONDON — March 20 marked five years since U.S. President George W. Bush launched the invasion of Iraq. Can Iraq emerge from this ordeal as a place where people lead reasonably safe and happy lives?

The American troops will leave eventually, and probably quite soon, but that is unlikely to be followed by an orgy of violence. The civil war has already happened, and most formerly mixed neighborhoods and villages are now exclusively Shiite or Sunni. That, as much as the "surge" in American troop numbers, is why the civilian death toll has dropped significantly over the past year.

Between 4 million and 5 million Iraqis have fled their homes (out of a population of less than 30 million), and most of them will never be able to return to those homes. Half of them are still in Iraq, and most of the rest are in neighboring countries and will ultimately have to return. They will eventually find somewhere safe to live, and they will start to rebuild their lives.