I urge you to go the BBC’s iPlayer and catch up with Iran And The West. This is history documentary of the highest order by the legendary Brooke Lapping, with star producers such as Norma Percy, Brian Lapping and Dai Richards.

It tells the compelling story of Iran’s revoution three decades ago and the way that relations between Washington and Tehran seem to have been at the centre of international affairs ever since.

I was privileged to watch part two with a bunch of other media folk, which was apt because it is clear that media coverage was a vital component of the diplomacy. The hostage-taking, for example, was played out through Western media, putting pressure on the governments of France and US to make compromises with Iran.

This series has total access to all the critical people. It was full of wonderful archive and delicious detail. And it reminds us that individuals and happenstance matter. So when the reformist Iranian President Khatami wants to talk to the American people, he choose to talk to CNN,

Now it happens that the chief correspondent of CNN was Christiane Amanpour who was in a romantic relationship with a certain Jamie Rubin, a high up US State Department official. He briefs her on the kind of questions that might elicit a response from Iran that would allow diplomatic wheels to turn.

The so-called CNN Effect is much discussed in media studies circles. Does the media drive diplomacy? Do governments do things to generate media coverage? This vingnette was just a detail in a sweeping drama of geopolitical, religious and military forces. But this documentary reminds us that journalism can tell historic stories as well as play a part in them.