In the House of Representatives, conservatives and oil-state Democrats want to make sure the oil industry doesn’t lose one of its biggest customers. They’ve been trying to repeal a 2007 law that prohibits the military from buying oil from tar sands and liquid fuels produced from coal. Never mind that those fuels consume far more water and produce far more carbon emissions than conventional oil, or that the convoys needed to deliver fossil fuels to the front lines are arguably the military’s greatest vulnerability and the soldiers’ deadliest duty. More than 3,000 contractors and soldiers were killed trying to protect fuel and water supply lines in Iraq and Afghanistan from 2003 to 2007. Last year, ground convoys were attacked 1,100 times