Make friends with the Iraqis. Stay out of politics and religious arguments. Try speaking Arabic - even if you're not good at it. No matter how badly you do it, they will like it. Be generous with your cigarettes. Remember that every American soldier is an unofficial ambassador of good will. American success or failure in Iraq may well depend on whether the Iraqis like American soldiers or not.
.....from the 1943 book Instructions for American Servicemen in Iraq During World War II...published by the U.S. Army...now in its second printing.

The book includes an updated foreword from Lt. Col. John Nagl, who served in Iraq with the 1st Brigade of the 1st Infantry Division. He writes about wishing he read the book before going to Iraq's Al Anbar province in 2003. "Some of the guidance in this little book is eerie to anyone who has fought in Iraq recently. It is almost impossible, when reading this guide, not to slap oneself on the forehead in despair that the Army knew so much of the Arabic culture and customs, and of the importance of that knowledge for achieving military success in Iraq, six decades ago - and forgot almost all of those lessons in the intervening years."