A fatal stabbing in Illinois, a gun pointed at protesters in Pennsylvania, vandalism at synagogues and harassment of staff at a Palestinian restaurant all are raising fears that the war between Israel and Hamas is sparking violence in the United States. The tensions follow a familiar pattern of crimes against Jewish and Muslim communities rising when conflict erupts in the Middle East and Americans have been killed or taken hostage. “We have a two pronged threat to American faith communities,” said Brian Levin, founding director of the Center for the Study of Hate and Extremism...