What is the difference between being able to produce a nuclear weapon and actually producing one? (None)

Although I am not surprised that the same facts can be interpreted very differently (particularly by the media), it is a point that is always worth stressing:
"If you look at the “2012 Worldwide Threat Assessment” presented on February 16 by Director of National Intelligence James R. Clapper to the Senate Armed Services Committee, and compare it with the “2011 Worldwide Threat Assessment,” you find a startling development. Last year, the assessment was “we do not know whether [North Korea] has produced nuclear weapons, but we assess it has the capability to do so.” This year it is, “North Korea has produced nuclear weapons.”" [Original links preserved, emphasis mine]