A classified military assessment of Iraq ’s security forces concludes that many units are so deeply infiltrated by either Sunni extremist informants or Shiite personnel backed by Iran that any Americans assigned to advise Baghdad’s forces could face risks to their safety, according to United States officials. The report concludes that only about half of Iraq’s operational units are capable enough for American commandos to advise them if the White House decides to help roll back the advances made by Sunni militants in northern and western Iraq over the past month. Adding to the administration’s dilemma is the assessment’s conclusion that Iraqi forces loyal to Prime Minister Nuri Kamal al-Maliki are now heavily dependent on Shiite militias — many of which were trained in Iran — as well as on advisers from Iran’s paramilitary Quds Force. Shiite militias fought American troops after the United States invaded Iraq […]