The Chilcott Inquiry is now focused on the legality of the invasion of Iraq by British forces, or rather the way in which the transparent illegality was ignored by a strong-willed ruling duo of Blair and Brown, with the former convinced that a quick win would vindicate his leadership and he would enter the pantheon alongside Margaret Thatcher. But while profoundly important in the sense that it reveals the root-canal rottenness of the once lauded civil service and its independence, the more important issue that Chilcott is unlikely to confront is the way that Blair and Campbell lied to the British public. Of course they did so convinced that some remnant of a chemical bomb or dust from a biological experiment would be found sufficient to justify their claim that there were weapons of "mass destruction" that might have threatened Britain/the world/someone - and how were they to know that Saddam didn't have enough.
Thus, while technically demonstrating that they were truthful, the larger misleading - that Saddam was an active threat in some way - would be swept away. I wrote at the time about the Campbell version of 'truth' in which technical veracity is used to drive through a perception that he and his master understood was what they wanted people to believe but not what they believed (a good a human definition of lying as you can get).
In this case they backed invasion because, after years of no-fly zones over sections or Iraq and the embargo they were well aware that however tight his internal grip on power was, he was an easy picking militarily. They invaded, in other words, because he was not a threat and would not be able to resist the US, and would thereby provide a marvellous symbol for the supremacy of democracy (not to speak of revenge for 9/11).
In the process Blair wrote in the introduction to the public dossier that set out his case and in his speech to parliament that Saddam was "manufacturing" chemical weapons. Not only was he not doing so, he could not have been doing so without the US and UK knowing because it was technically impossible for him to manufacture the toxic materials entailed without this being clearly visible. Although he was not alone, one person in particular was aware of this, Ron Manley. Manley had dismantled the considerable stocks of Iraqi chemical weapons under UN auspices after the first Iraq war. He destroyed their factories, knew their weapons makers and their technology. He was employed part time after his retirement in the Ministry of Defense. But he was never asked for his assessment of the situation. In fact nobody asked him except openDemocracy. Caspar Henderson and I interviewed him at length. You can read it here. The UK press ignored it at the time.
Manley thought that Saddam must have retained some weapons to frighten his own people. But he was confident that he could not have been making them and, for reasons he explains about their decomposition, that no militarily significant stocks would have survived.
Nonetheless, while he didn't drive the point home, I did in an editor's note and it was obvious enough. On this clear and precise point Blair and his factotum Campbell were factually wrong and no intelligence service could possibly have misled them.