The 9/11 Commission was established in late 2002, but it had an inauspicious start. The Bush administration had strongly opposed the establishment of such an inquiry and it took a sustained campaign by some of the 9/11 families and their supporters in Congress to make it happen.
Originally the commission was to be chaired by Henry Kissinger, the former secretary of state, while George Mitchell, the former Democratic majority leader in the Senate, and chair of the Northern Ireland peace talks was due to be its vice-chair. Controversy about perceived conflicts of interest arising from Kissinger's multinational consultancy work and Mitchell's law firm meant, however, that they both stepped down before the commission even began its work.
Instead Thomas H Kean, a Republican former governor of New Jersey, was appointed to chair the commission, while Lee H Hamilton, an Indiana Democrat who had been a member of the House of Representative for 35 years, was appointed as vice-chairman.
They were joined on the commission by eight others, four nominated by the Republicans and four nominated by the Democrats. While many of the 10 commissioners did have a legal background, most were former Congress or cabinet member and all were chosen primarily because of their political standing or because of their involvement in previous inquiries.
The inside story of how the commission went about its task is told in Without Precedent, a book co-authored by Kean and Hamilton and published in 2006. The relationship between the two men was central to the inquiry's success as was their determination to operate on a bipartisan basis. Their two mantras throughout their work were "go to the facts" and "stick to the mandate". They knew, given the range of issues they were inquiring into, that they could not turn up every fact or resolve every dispute, but they were determined to do the best possible job and they resisted calls to extend their investigation beyond the scope of their mandate.
Under that legislative mandate the commissioners were charged with "examining the facts and causes relating to the terrorists attacks". In doing so they were required in particular to examine the workings of the intelligence and law enforcement agencies, diplomacy, immigration and border controls, the flow of assets to terrorists' organisations and the operation of commercial aviation. They were also required to examine the impact that congressional oversight and resources allocation had on the level of preparedness for such incidents.
It's clear from the book that Kean and Hamilton were particularly alert to the fact that any leaking of information would undermine the inquiry's credibility - not least because their work would necessarily involve them accessing some of the most sensitive classified information.
The commission ultimately employed a staff of 80 lawyers, researchers and experts, all of them on short-term contracts. They sifted more than two million pages, conducted 1,200 private interviews and prepared background papers for the commissioners on a range of topics touching on the inquiry.
Most of the inquiry's work was done in private but it did hold 12 days of hearings, which attracted blanket media coverage.
These hearings were often emotionally charged and they included testimony from some top officials from various agencies and administrations whose actions were being investigated.
The commission had wide powers to subpoena documents but used them sparingly, conscious of the need to avoid lengthy legal challenges, preferring instead where required to leverage public and political pressure to compel the various state agencies to comply with their requests.
A number of aspects of the inquiry and its work are particularly interesting in the context of recent debates on this page and elsewhere about the cost, effectiveness and duration of tribunals of inquiry in this country.
First, the 9/11 Commission completed its task expeditiously. It began its work in early 2003 and published a report on July 22nd, 2004, a considerable achievement given the scope and complexity of the investigation.
Second, the subsequent report received widespread acceptance. It was written in a journalistic rather than a legalistic style and distributed through bookshops. It became an immediate bestseller when 100,000 copies were sold on the day it was published, and more than 350,000 copies were sold by the first weekend. The commission's website received more than 50 millions hits on the day the report was published.
Although the findings did not meet with universal approval, the inquiry's report was welcomed as comprehensive and balanced by an overwhelming majority of media commentators, politicians and the public.
Third, most of the commission's recommendations were implemented. Within a week of the publication of the report president Bush announced that he was issuing several executive orders in response - including one to appoint a director of national intelligence and another to establish a national counter-terrorism centre. The Senate and House of Representative, which were both due to rise for the summer recess the day the report was published, took the extraordinary step of scheduling a series of congressional hearings on the commission's recommendation during the month of August. By October a series of legislative proposals to implement the key recommendations had been published. On December 17th, 2004, Bush signed a bipartisan act which effected the most dramatic reform of the United States' intelligence capabilities since 1947.
Finally, the commission provided phenomenal value for money to the American tax payer. It initially had been granted a budget of just $3 million (€2.05 million). When the commissioners realised the full extent of their task in March 2003, they persuaded Congress to increase this budget to $14 million. Not only did the commission complete its monumental task within a relatively short timescale and in a manner generally accepted as comprehensive, but they did it within budget.
Indeed at the end of their work they returned $1.4 million to Congress.