Adam Curtis' latest (March 2007) documentary series The Trap explores the modern idea of freedom. It's interesting because he uses the example of US foreign policy in Nicaragua to show how a limited conception of freedom (as freedom from constraint) leads to the perverse belief that people can and should be forced to be free. This from Wikipedia:

"The final programme focussed on the concepts of positive and negative liberty introduced in the 1950s by Isaiah Berlin. Curtis briefly explained how negative liberty could be defined as freedom from coercion and positive liberty as the opportunity to strive to fulfill one's potential."

You can see the full programme here. Look out for contributions from Elliot Abrams, assistant US secretary of state 1981-1989 and Robert Parry, Associated Press reporter in Nicaragua in the 1980s.