The intelligence agencies’ 2005 finding that Iran was pursuing a nuclear weapons program was consistent with strong warnings about Iran issued at the time by Bush administration officials, including Vice President Dick Cheney and John R. Bolton, then the under secretary of state. But there has been no indication that policy makers sought in any way to influence the agencies’ conclusions on Iran, which like all intelligence assessments are supposed to be immune from political pressure.
The reason for the change in assessment according to the NY Times, a number of changes - leadership, sources, and methods of evaluation:
Current and former intelligence officials insist that much of the 2005 Iran report still holds up to scrutiny.
At the same time, they acknowledge that in retrospect, some of its conclusions appear to have been thinly sourced and were based on methods less rigorous than were ultimately required under an intelligence overhaul that did not begin in earnest until later.
It was also written by some of the same team that had produced key parts of the flawed Iraq estimate. Robert D. Walpole oversaw both reports as the national intelligence officer responsible for assessing illicit-weapons programs.
source: NY Times
Personally I hope that this estimate is the more accurate and that it is the beginning of a long term trend in more accurate analysis but I'm not holding my breath, after all one of the roots of the word analysis is anal - as in pulling it out of their asses.
Iran, Nukes, WMD, CIA, NY Times, Media