The uncompleted al-Rahman mosque is seen from a distance from U.S. Secretary of Defense Chuck Hagel's helicopter, as it flies over the city, in Baghdad, December 9, 2014. U.S. Defense Secretary Chuck Hagel arrived in Baghdad on Tuesday as the United States expands its presence and touts progress against Islamic State militants four months after starting a campaign of air strikes in Iraq. REUTERS/Mark Wilson/Pool (IRAQ - Tags: POLITICS CIVIL UNREST RELIGION BUSINESS CONSTRUCTION CITYSCAPE)