A remarkable clash between two key American allies in the Middle East burst into the open here on Wednesday as the Iraqi prime minister publicly criticized the Saudi air campaign in Yemen and a top Saudi official retorted that there was “no logic to those remarks.” The exchange, driven by sharply opposing views of Iran in the region, reflected the challenges facing the Obama administration as it tries to hold together a diverse coalition, including Sunni Arab states and Shiite-dominated Iraq , in the fight against the Islamic State, also known as ISIS . Iran is a sometimes patron to Iraq but an ideological archrival to Saudi Arabia . The United States remains caught in a difficult balancing act as it […]