Iraq war: 'We are systematically programmed to kill'

Sergeant Rudy Reyes was one of a small group of elite Recon Marines sent ahead of the main invasion of Iraq by coalition forces in 2003.

His mission was to help clear the path to Baghdad, making it easier for the regular US Army to reach the city.

Sergeant Reyes recalls fighting for three weeks with no sleep and describes the firepower used in battle by US forces as "god-like".

After the years of chaos and violence that followed the invasion, the US Marine considers whether it was all worth it.

You can watch 'Once Upon a Time in Iraq: Episode 1' on Monday 13 July at 9pm on BBC Two, or afterwards on BBC iPlayer.