American success or failure in Iraq may well depend on whether the Iraqis ... like American soldiers or not. ... One of your jobs is to prevent Hitler's agents from getting in their dirty work. The best way you can do this is by getting along with the Iraqis and making them your friends. ... Every American soldier is an ... ambassador of good will.
Kerbela (and) Nejef ... are particularly sacred to the Iraqi Moslems. ... It is advisable to stay away from them.
Apparently the folks running the current occupation hadn't read this book.
The complete document is available as a PDF right here.