Great weight should be given to the judgment of professionals on what information, if disclosed, would harm national security.

When I was at the CIA I asked my civilian advisory board to tackle some tough questions. Among the toughest: In a political culture that every day demands more transparency and more public accountability from every aspect of national life, could American intelligence continue to survive and succeed? That jury is still out.

There is no part of the executive branch that more exists on the outer edge of executive prerogative than the American intelligence community - the intelligence community, CIA, covert action. My literal responsibility as director of CIA with regard to covert action was to inform the Congress - not to seek their approval, to inform.

ISIS is a learning enemy, and former Deputy Director of NSA Chris Inglis says that they have gone to school on the documents released by Edward Snowden and have changed their communications practices.