In this Sunday, Feb. 15, 2015 photo, Shiite militia fighters walk on the frontline just outside of Kirkuk, Iraq. When the Islamic State militants blitzed across northern and western Iraq last year, tens of thousands of Shiite men answered a call-to-arms by the country’s top Shiite cleric, Grand Ayatollah Ali al-Sistani, to defend the nation against the Sunni extremists. Now the Shiite militiamen have arrived in Kirkuk, long one of Iraq’s most hotly disputed territories, and have made a string of bases just 10 kilometers (six miles) from the city their home. (AP Photo/Bram Janssen)