"You will be killed." "Excuse me." "You're going to be pilloried, lambasted. Yeah, you're going to be unpopular." That was the conclusion of a colleague, someone with a lot of experience in the Middle East after watching just the opening minutes of my new FRONTLINE documentary, Inside Assad's Syria, which premieres tonight on PBS stations and online. "Why?" "It's the very idea of it -- going into regime-held territory. Too many people have a view of Syria that this will inevitably challenge. This is an invitation for abuse." Another colleague told me before I left, "You will get the charm...