There’s no better way of putting it than to quote Rumsfeld directly. Mushroom Cloud indeed!
"As we know, there are known knowns. There are things we know we know. We also know there are known unknowns. That is to say, we know there are some things we do not know. But there are also unknown unknowns — the ones we don't know we don't know," Rumsfeld said in 2002, suggesting Iraq could have been giving terrorists weapons of mass destruction despite the fact there wasn't much evidence of it.
"Simply because you do not have evidence that something exists does not mean that you have evidence that it doesn't exist," he said in 2002, regarding the same topic.
"I believe what I said yesterday — I don't know what I said, but that I know what I think — and I assume it's what I said."
"Learn to say, 'I don't know.' If used when appropriate, it will be often," he wrote in his book,"Rumsfeld's Rules."
"I would not say that the future is necessarily less predictable than the past. I think the past was not predictable when it started."
"As you know, you go to war with the army you have, not the army you might want or wish to have at a later time," he told troops in 2004.
"I don't do quagmires."
"I don't do diplomacy."
"I don't do foreign policy."
"I don't do numbers."
"I don't do predictions."
On life
"The only thing that should be surprising is that we continue to be surprised," he said in his book, "Rumsfeld's Rules."
"If you are not criticized, you may not be doing much," he also said in the book.
"Oh, Lord. I didn't mean to say anything quotable."