Obama's Perforated Red Line

"What we saw in Syria last week should shock the conscience of the world. It defies any code of morality. Let me be clear: The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders by chemical weapons is a moral obscenity." - John Kerry

Before declaring what is and is not a "moral obscenity," the U.S. should establish some legitimate claim to a "moral authority."