Not Iraq but Lousiana is the latest front in the battle for hearts and minds. A rocket-propelled grenade explodes as a convoy of American troops passes through an Iraqi village. Maimed market traders cry for help from army medics – then a suicide bomber blows himself up in their midst. This is not the Middle East though – it’s a US army base in Louisiana. And along with the battle training, soldiers are being taught “cultural awareness”, and how to negotiate with local leaders. We have been to Fort Polk to see America’s latest weapon against an insurgency it didn’t see coming.