No political thriller, be it literature or film, is complete without a ticking time-bomb scenario. In a classic example of life imitating art (anyone know the full Oscar Wilde quote?) Iran watchers have readily adopted the metaphor to describe Iran's long march toward nuclear the bomb. 

The problem is that no one can seem to figure out exactly how much time is left is left on the clock or how fast it is ticking.

The Israelis claim that Iran will have the capacity to build a crude nuclear weapon by the end of the year. In July CJCS Adm. Mullen seemed to agree with Jerusalem's assessment. But the Israelis have been saying the same thing since the mid-1990s and Mullen's statement contradicts previous US intelligence reports. 

So what are we to believe?

Joshua Pollack, an intrepid blogger at armscontrolwonk.com, does a great job of hashing out what these numbers mean, how they are derived and ultimately why the ticking time bomb metaphor isn't a particularly good way to conceptualize Iran's nuclear program. Check out the full article and subsequent debate (armcontrolwonk.com's readers are smart folks) here.