BAGHDAD, Dec. 29 -- Two senior Iranian operatives who were detained by U.S. forces in Iraq and were strongly suspected of planning attacks against American military forces and Iraqi targets were expelled to Iran on Friday, according to U.S. and Iraqi officials. The decision to free the men was made by the Iraqi government and has angered U.S. military officials who say the operatives were seeking to foment instability here. Special Report Washington Post stories and multimedia reports about Iraq, Afghanistan, the War on Terror and more. • Faces of the Fallen • Veterans: In Their Own Words • Afghan...