There are too many unknowns, too many factors that we may not have yet considered.
Donald Rumsfeld coined this phrase in response to
questions about whether terrorism
intelligence collected by government agencies was being shared with all other security agencies.
Q: But seriously, Mr. Secretary, are you confident that all the
intelligence gathered has been adequately shared, all the
intelligence that Defense and the military has gathered has been adequately shared with other security agencies in the government?
Rumsfeld: Well, of course you don't know what you don't know. All I know is that we get a great deal of intelligence. We see that the individuals responsible for force protection in the
United States and elsewhere around the world have it as rapidly as is possible. They then make their judgments as to how they're going to behave with respect to it.
(...)
I feel that we know what we know and we don't know what we don't know.
