Frontlines of Journalism: The Big Lie

When BBC International Editor Jeremy Bowen asked President Bashar al-Assad about the well-documented Syrian practice of dropping barrels full of explosives on areas held by the rebels he was confronted by a repeated lie. The question for journalists is how they deal with that - and what happens when the lie machine is turned on the journalists themselves. Revisiting some of the most difficult stories he's reported on, Jeremy looks at some of the obstacles that stand between journalists and the truth