…Three stages are involved in the evolution of a military nuclear capability: a delivery system, a capacity to enrich uranium and the production of nuclear warheads. Iran has been augmenting the range and number of its missile systems since at least 2006. Its enrichment capacity — long underreported to the International Atomic Energy Agency — has been expanded to thousands of centrifuges (the instruments that enrich uranium to bomb-grade material). The level exceeds any reasonable definition of peaceful uses authorized by the Non-Proliferation Treaty. The inevitable culmination is a nuclear weapon.
To draw the line at proscribing an Iranian nuclear weapon — as some argue — would prove unmanageable. Once the requisite amount of fissile material has been produced, constructing and equipping a warhead is a relatively short and technologically straightforward process, almost certainly impossible to detect in a timely fashion.
If so ineffectual a red line were to emerge from a decade of diplomacy by the permanent members of the Security Council, the result would be an essentially uncontrollable military nuclear proliferation throughout a region roiled by revolution and sectarian blood-feuds.
(Excerpt) Read more at washingtonpost.com