It was about 13 years ago. Recall that the famous 2007 NIE followed a similar deep dive.
From the UK Iraq Inquiry a few years back:
TIM DOWSE: Although it was unusual then, it has become notquite standard practice, but much more common since,because we did, partly as a result of the Butler Review,establish a challenge team, and there were a series ofpapers over the next few years, none of them relevant toIraq,where we reviewed our judgements.We conducted a very major review,on the Iranian nuclearprogramme in, I think, 2006. That was, for fairly obviousreasons, because of the Iraqi experience. We wanted tolook at it, take a completely fresh look, and say: is thisreally for a military purpose?
So what did they conclude then? And In the aftermath of the Israeli document heist, what does UK believe now? I expect to post quite soon on why what they and others conclude on this will matter in the ongoing deliberations of the IAEA Board of Governors after Ambassador Rafael Grossi takes over at the Secretariat beginning next week.
I don’t think their public conclusions have changed in recent months.