There is probably, at best, no more than a one-in-five chance of the stand-off between Iran and the international community being resolved without conflict. The game of high-stakes, nuclear poker Tehran is playing probably has many hands to run. Yet the theocrats in charge of Iran are not just confident but provocatively cocky, which augurs badly for any resolution that might satisfy the world about their nuclear ambitions. A firm, united but carefully calibrated response nevertheless offers a slim hope of a negotiated outcome.

At the same time, every policy option should have hard-wired into it the fact that confrontation suits the current Iranian regime, which is ultimately based less on religious zeal than on vested interests built up after the 1979 Islamic revolution. The ruling mullahs are widely despised by their people, but Iranians across the political spectrum support their country's right to both technology and deterrence - making the nuclear controversy a God-given issue around which to rally the nation.