Gen. Michael Nagata is promising to build a new force to destroy ISIS, but lawmakers worry he has been given an impossible mission. As lawmakers prepared to take a risky and fateful vote on Obama’s plan to train and equip the Syrian rebels, the man who assured them it could be done was Gen. Michael Nagata, Obama’s point man for the mission to build an ISIS-killing army in Syria. There are skeptics both inside and outside the government who doubt Obama’s new plan to arm the Syrian rebels can work. First of all, the administration has said for years that...