Was that madness in her eyes?

"I had serious misgivings about whether the interview was a good idea. People sometimes ask me if there are any questions that are out of bounds and the answer is 'yes', there are limits. One of these limits to interviewing people in the public eye concerns the likely damaging effect on innocent and vulnerable family members. I had grave anxieties about the potential impact on her sons, Wills and Harry."

Interviewing Princess Diana without asking questions that were sensitive and potentially harmful to her children was always going to be very difficult. I believe these questions to be crucial to the interview; not asking them would have made it a waste of time.

I was surprised and relieved at how it came out. We saw a woman in control, articulate, sensitive and protective of her sons. She is still healing. She is vulnerable and troubled. The Royal couple are showing behaviour typical of people in marital therapy. But instead of being in the same room with a counsellor, they are battling separately on TV.

I expected her to say that a divorce was inevitable but she did not. It was the only moment when she asked questions herself. Each has forgiven the other for adultery. If you read through the text of the interview and her references to Prince Charles, there is very little venom or bitterness. That venom is addressed to the Palace. If the Prince is enraged, he should be advised to calm down.

I think she was acknowledging last night that she sees the relationship as a great deal more complicated than we have recognised. She was attacking the view that she was just going to go away. She's a tough cookie and she is not going to. The classic quote was 'there were three people in the marriage' and that is the situation that has to be resolved.

Is the marriage completely over? If you took a complete step backwards, could you put your hand on your heart and say that? She has not written it off. It is as if it is left hanging in the air.

Take the way she kept on talking about her husband, only once referring to him by his first name. She used the words 'my husband' again and again. It was highly significant. If you are sympathetic to her you would say she is saying: 'He belongs to me'. If you thought she was political, then she was saying there is still a price to pay for her treatment and she will not let him go until it is paid.

She drew on her experience as being the child of divorced parents, and made something of the fact that children of divorcees don't want the pattern to continue. Most commentators are not taking account of that. They make too easy an assumption that divorce is the obvious option. They are obsessed, male-like, with tidying it up but she knows in her nature that it is not going to be tidied up. You can't extricate yourself like that from a marriage, and she is not going to go away.

On reflection, having seen the interview, I take back the anxieties I had about the children. She handled references to her problems and the children very sensitively. For the children this kind of interview is going to be distressing and they will have been distressed by Charles's too. But she did as much as she could for them.

Doing this kind of interview is a cathartic experience. It is quite common now for people to say they want to set the record straight. Hearing her account gives it an authenticity. We already knew about the relationship with Hewitt, the bulimia, the self-mutilation. But there is a way in which you have to tell your story to make it real, to move on.

Given what she told us about bulimia, she has not been a strong woman all the time. For the reasons she told us, she has a lack of self-esteem and self-knowledge, but now she is building on that. But she will derive a considerable amount of psychological support from people and this broadcast is part of the process of gaining that support, ending that sense of isolation she complained of.

Although she seemed strong, she is still healing and there are rocks and trouble ahead. She has been through the mill and when she talked pretty candidly about the psychological aspects of her state they seemed very authentic. That would help her to reach large numbers of people, there would be an empathy.

Far from seeming unstable, she was in control. The setting suited her. Control is important, and she has more self-knowledge now. But her predicament is precarious.

All in all it was an excellent performance. Rehearsed? It looked as if it was. I never saw her fazed. She was well prepared. You can train people, and they will still not be perfect but she was very good. She was a professional, a woman with two children, good looking, a very good actress.

It is a tough life being royal. Common experiences were revealed in her interview and her husband's. Charles acknowledged that there were photographers everywhere. They shared the difficulties, the dreadful experiences; you can make the marriage a joint operation in that way. In other words they had to be even more united than in a normal marriage.

They have negotiated the wreck of adultery and each seems to me to have forgiven the other. I would be intrigued to know how much help they got as a couple. Sometimes people at the top get very little help indeed. Prince Charles is an interesting man and I think there is a great deal more to Diana than she has been given credit for. She has learnt a great deal; now she is older, wiser, and shrewder."