Yousef Aid Ahmed has memorized the places where his four brothers' bodies laid after they were killed by US marines, he said. The family recounts that November day in 2005 and says it was a massacre of the brothers, along with 20 other people, following a roadside bomb in Haditha.

For the mission's sake, our country's sake, and the sake of the men who carried the Division's colors in the past battles - who fought for life and never lost their nerve - carry out your mission and keep your honor clean. Demonstrate to the world there is "No Better Friend, No Worse Enemy" than a U.S. Marine.

The United States has been essentially engaged in an ongoing war that most people date from 2001. That war has taken us to Afghanistan, to Iraq, in a lesser way to other countries - Libya, Somalia, Yemen.

The most important six inches on the battlefield is between your ears.

There are some people who think you have to hate them in order to shoot them. I don't think you do. It's just business.

What concerned me was that [James Mattis] played not only a critical role as a battlefield commander in Fallujah, but also, afterwards, when he was promoted to various other higher-ranking positions, he served as a convening authority in court-martial proceedings against various marines who had been accused of atrocities - for example, in the Haditha massacre, where a group of marines went on a killing spree after one in their unit was killed.

Be the hunter, not the hunted: Never allow your unit to be caught with its guard down.