Though the intelligence failures surrounding Iraq are now well known, recent history is abundant with examples of flawed intelligence that have affected key national security decisions and contingency planning.  They include, for example: the poor quality of the intelligence gathered on the ground in Viet Nam; the underestimates of the scale of the Soviet Union’s military efforts during the Cold War; a lack of awareness about the brewing Iranian revolution that forced the Shah, an American ally, to flee the country; the failure to detect the preparations for India’s nuclear test; and consistently underestimating the number of missiles that China had deployed along the Taiwan Straits.  For Iraq, there was a similar pattern of intelligence estimates that had dangerously miscalculated Saddam Hussein’s nuclear capability.  After the Gulf War, UN inspectors were surprised ti discover that Iraq had been no more than a year or two away from having enough fissile material top produce a nuclear bomb.

David Kay, the chief UN weapons inspector in 1991, believed it would have been only twelve to eighteen months until the regime reached “regular industrial-scale production of fissile material, ” or enriched uranium, that could be used in an atomic bomb.

From Known and Unknown by Donald Rumsfeld