It is as wide and full a remit as any previous inquiry has had.
No inquiry has looked at such a long period. No inquiry has the powers to look in so much breadth. For while Franks looked only at the run up to the Falklands conflict, the Iraq Inquiry will look at the run up to conflict, the conflict itself and the reconstruction so that we can learn lessons in each and every area.
Brown later noted that It has been announced in a Prime Ministerial statement to the House, not in a written statement, as the Franks inquiry was.
But this misses two important and central points.
Firstly, how far public expectations have shifted. As Tony Wright argued in response to the PM in the Commons, a private privy counsel inquiry may have been what was expected 25 years ago, but there is clear demand for a more open process today. That is an obvious context when the need to open up poiitical institutions and restore public trust is the theme of the moment. The Prime Minister did not fully acknowledge or meet this point in arguing that the House of Commons would get to debate the inquiry report.
Secondly, the nature of the Iraq conflict as the publicly controversial and contested issue in British foreign policy, at least since Suez half a century before, in dividing Parliament, political parties and the public.
That last point can be argued both ways. Tom Harris is right to say, in response to Next Left's earlier post, that there is no inquiry which could persuade those with the most deeply held views against, or indeed for, the war to change their minds.
An inquiry can not change the history of what happened. But that does not mean that there is no point to an inquiry. And the views of what might be called the reasoned critics were worth taking on board as fully as possible. Indeed the case for as public a process as possible was today made by those who had supported the war as well as those, like ex-LibDem leader Ming Campbell, who were against the war in 2003.
The choice was not between a full-scale public inquiry and the inquiry as announced. It would be perfectly possible for the inquiry to take evidence on particular military, intelligence and national security issues in private, while holding several public witness sessions.
Nor is it to impugn the public service or expertise of those selected for the inquiry to note that its overall composition will look to many people like a rather British Establishment affair.
The case for an inquiry was important.
Gordon Brown deserves credit for accepting it, and I warmly welcomed this when he first did so.
It was not inevitable that he would do so - and there were certainly Whitehall voices against it, and political arguments that it would be a distraction or simply again increase the salience of Iraq. So Brown could have - as his predecessor did - stuck with the argument that there had already been four inquiries into various aspects of Iraq, that much of what would be found out was already known, and that nothing would in any event convince the critics.
But the government has now fumbled the public politics of the inquiry twice - getting caught in process arguments first about the timing of an announcement, and now about the nature it will take. Perhaps some criticism was inevitable - but a broader approach would also have had broader support, and that is a chance that has been missed.
Perhaps the government - and the inquiry itself - could still look at how to engage better with public interest in its deliberations. It may perhaps now primarily be for civic society to work out how to supplement the official inquiry with further (non-partisan) public deliberation on the issues at stake.
The inquiry would have more public engagement and confidence if its next appearance in public is not held over until it is ready to publish its final report.