And I wonder, in your own experience, when were you closest to going along to get along in any of the advice that you gave, particularly to strong American governments and military who are so dominant and so overpowering?

Well, I think that I have my share of standing up and giving my view in circumstances where it might be unpopular.

I remember one meeting of the US military, US led military team looking at the forthcoming campaign in Afghanistan, where I was invited to speak.

And I ventured the opinion that actually talking to the Taliban and trying to reach a political accommodation with them might be necessary.

And I remember one US general who subsequently became quite well known, leapt to his feet, rather red of face, and told me that these were women hating, murdering so-and-sos.

And the only thing to do with them was to defeat them militarily.

And that didn't turn out so well.

How do you sit with someone whose actions you find repugnant without pretending to like them, without giving them comfort? And what would you not trade, whatever the price?

How do you account for that?

I think there are two things to say.

The first is that the demonstrations in January were interesting because for the first time at that scale, I think it would be fair to say, we saw a combination of economic grievances, very often from the poorer segments of society who are just finding it incredibly hard to make ends meet, given the fact that the Iranian economy is pretty much a basket case.

And they were allied to people who had a more of a political and social agenda against the regime.

So it was quite dangerous for a moment.

The problem has been that there is no connective tissue at the present between demonstrations on the street and regime change.

There is no charismatic leader in Iran around which opposition can coalesce, largely because, of course, they've all been dealt with by the regime over the years.

What's your sense? And as a professional diplomat for many, many years, do you think diplomacy could still offer a way out, or are we beyond that now?