Syrian rebels who overthrew the dictatorship of Bashar al-Assad on Sunday are reportedly executing their opponents, imposing Islamic sharia law, and threatening non-Muslim minorities, including the Kurdish population in the north. Videos are circulating on social media showing Syrian rebels killing people associated with the regime — some of whom may have been part of the state security services, and others who appear to have been ordinary employees. The New York Times reported Tuesday: Islamic State forces on Tuesday killed 54 people in the Homs region in central Syria who had been part of the Syrian government’s military and fled...