Iraqi Prime Minister Nouri al-Maliki has announced that he will step aside and support his designated successor. The announcement Thursday came hours after Mr. Maliki claimed the president's nomination of Haidar al-Abadi was illegal and that he would fight it in court. The new prime minister is tasked with uniting Iraq's various ethnic and religious groups in an effort to defuse the threat by Islamic State militants advancing from the north. Zlatica Hoke reports.