In Iraq everyone privately knew the WMD thing was a pretext, and this assumption underpinned all our political work. No-one was 100% certain of the real aims. Still today. So we made it up.
Whether any of the officials who are now coming forward felt similar pangs of conscience at the time about the discrepancy between what they knew and what their government was saying is not known, but what is certain is that none of them were prepared to act on them if they did.
So has the proposal for a WMD-free zone in the Middle East finally got legs? Many would say that the very idea is an absurd fantasy - that it cannot possibly be achieved, given the tensions and complexities that exist in the region.
Recent remarks by the head of MI6, Sir John Sawers, leave us wondering if the Secret Intelligence Service is preparing to 'fix' intelligence on Iran, as his immediate predecessor, Sir John Scarlett, did on Iraq.
So here's the scenario. A sovereign nation in the Middle East is accused of developing weapons of mass destruction. The dictatorial leader is portrayed as psychotic and deranged across the western media, seemingly capable of anything.
Countering the spread of WMD is one of the most important challenges we face in building a peaceful and secure 21st century. Whilst public attention is always focussed on nuclear issues, that doesn't just mean countering those illegal weapons programmes.