US may work with Iran against terrorists

PARIS — Diplomats from around the world pledged to fight Islamic State militants “by any means necessary” as Iraq asked allies to thwart the extremists wherever they find sanctuary. Iran and the United States ruled out coordinating with each other, leaving Baghdad’s government caught between two powerful and antagonistic allies.

Neither Iran nor Syria, which together share most of Iraq’s borders, was invited to the international conference in Paris, which opened as a pair of French reconnaissance jets took off over Iraqi skies. But the State Department left open the possibility...