March 6 (Reuters) - The United States will respond to Iranian attacks on civilians throughout the Middle East, the leader of the U.S. Central Command, Brad Cooper, said on Friday.Cooper said that Iran has attacked 12 different countries since the U.S. and Israel launched strikes on the Islamic Republic last week, including firing seven attack drones at civilian, residential neighborhoods in Bahrain on Thursday night."This is unacceptable and will not go unanswered," Cooper said in a statement.