Every week brings new reports of Muslims in America flocking to join ISIS. Those who aren’t killed in battle will eventually return to New York, to Los Angeles and to Minneapolis–Saint Paul. And they will stop being Iraq’s problem and become our problem.ISIS is more than just another terrorist group. It is now an Islamic State. Its followers and allied militias pledge to obey the Caliph of ISIS and reject all allegiances to other states and entities. Western ISIS recruits burn their passports to show that they are no longer citizens of those countries.Like most Salafists, ISIS members see our...