The White House's official policy of banning the word "Islam" in describing America's terrorist enemies is in direct conflict with the U.S. military's war-fighting doctrine now guiding commanders in Iraq and Afghanistan. John O. Brennan, President Obama's chief national security adviser for counterterrorism, delivered a major policy address on defining the enemy. He laid out the White House policy of detaching any reference to Islam when referring to terrorists, be it al Qaeda, the Taliban or any other group. But Army Gen. David H. Petraeus, the man tapped by Mr. Obama as the new top commander in Afghanistan, led the...