In response to a question about suspected Iraqi weapons of mass destruction seven years ago, then-Secretary of Defense Donald Rumsfeld famously said,"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." As tortuous as his formulation was, the notions he raised may be of some use putting recent developments regarding Iran's uranium enrichment program in proper perspective. The activities that we know of, such as Iran's uranium enrichment progress, are certainly of serious concern. But what will pose the biggest risk, and provide Iran with its most likely path to a weapons capability, is everything that we know we don't know.
Iran’s Nuclear Program: The Risk of the ‘Known Unknown’
