“What on earth are you two doing here?”, sighed Robin Cook. “We’re the flies on the Downing Street wall,” I sighed back with a forced attempt at levity. It was the afternoon of March 17, 2003, the day before the House of Commons debate on the Iraq War and resignation time for the top Labour opponent of Tony Blair’s policy. Even for the inhabitants of No 10 who were in full support of their leader this was not a happy hour.

“Flies on the wall?”, the ex-Leader of the Commons muttered softly. “You’re not the bloody only ones.” He pointed back towards his colleagues in the Cabinet Room, even then discussing events over which they had little real control. Then, with a lilting, almost singing, “ay, ay, ay, ay, ay”, he made his prearranged secret exit from the Prime Minister’s house.

That was four years ago, a wholly different era in Downing Street as well as in Baghdad. It has been an eerie task to return to the words and photographs that Nick Danziger and I took away from that 30-day assignment for this magazine inside No 10, inside Camp David, beside Tony Blair and his wartime team almost everywhere they went. The contrast between a once-bright confidence and the current brutal realisation can be felt on almost every page.

Within the hundreds of images, revisiting them frame by frame for this month’s National Portrait Gallery exhibition, the signs of doubts, fears and frustrations seem, not surprisingly, more prominent now. That is not just hindsight. It is a tribute, too, to what Nick Danziger saw. He is a photographer of few shots and, for long periods, his shutter hardly seems to click at all. He shoots only when he sees something. The picture on the previous page is just one of the remarkable results – showing, with a subtle precision, what Robin Cook meant by the “wall-fly” status of senior politicians in the war against Saddam Hussein.

March 20, 2003, 7:55am Tea before first War Cabinet

It is 7.55am on March 20. The Americans have dropped their “shock and awe” on Baghdad somewhat earlier than their best ally had been expecting. Before the first War Cabinet meets its members are musing on how they heard the news: Gordon Brown from the BBC World Service, Jack Straw from a policeman pummelling at his door, David Blunkett from Radio Five Live.

The setting is the rear hall of No 10. The man between the Chancellor of the Exchequer’s right eye and the Foreign Secretary’s left ear is Pitt the Younger, whose experience of wars (mostly Napoleonic) is certainly greater than that of anyone else in the room. The current Prime Minister is on this occasion out of shot. Tony Blair, no slouch now at war leadership himself, is behind the closed door to the right – with his chief of staff and security chiefs, in the meeting which ministers suspect is “the real meeting”.

In retrospect, there are only three men in this picture who could have kept Britain out of the conflict. The face of the first, the Attorney-General, Lord Goldsmith (third from right), does not suggest a man exhilarated by his long and agonised judgment that the war is legal, a view shared by uncomfortably few of his learned friends. He has been showing himself a highly political Attorney, contributing to discussion across a range of subjects far beyond the law, an enthusiasm noted by his colleagues with an approval that is caution-tinged.

The lowered eyes of the second, Gordon Brown, look thunderously at the camera. Five days before I had listened to the Chancellor of the Exchequer in the lower reaches of No 11, on a great gilt chair as though enthroned, while he put it to the Prime Minister, “What people ask me is why is there not just a little more delay”. He had received only crackle and snap for an answer – and was now on War Cabinet call to discuss “resource allocation”.

Jack Straw, who replaced Robin Cook as Foreign Secretary after Tony Blair’s second election victory, is the minister who has been most entwined in the negotiations about how long a delay there could have been. As the minister responsible for MI6 he has responsibility too for the promise from its boss, Richard Dearlove (out of sight in the security briefing at this moment), that weapons of mass destruction were assuredly there, in Iraq, and would assuredly be found. If Straw had been dissatisfied on either point, his Commons authority could have swayed decisive Labour votes. But on this first morning everyone affects to be satisfied – at least on the matter of Iraq’s illegal arsenal.

During our preparations for the National Portrait Gallery over the past few weeks, David Blunkett recalled to me that he had arrived that morning “with an expectation of an explanation”, most particularly on why the bombing had begun so soon. “Explanation” was what he hoped these daily morning meetings would provide for as long as the war went on. But “often we didn’t get it”. It was the “expectation” which tended to live on when the talking was over. Meanwhile most of the war counsellors in No 10 had to go home daily to partners, wives and children whose loyalty to the cause was sharply less than that of the Cabinet Room.

As the ministers sip their coffees and teas on March 20, there are issues more immediate than how they ever became a “War Cabinet” in the first place. Never mind Baghdad. How will the British people behave once the bombs have been dropped “in their name” against the protests of millions wearing “not in my name” T-shirts? In both Blunkett’s and Straw’s recollection of that morning the big doubt was whether there would be a “violent response at home”.

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