Self-defence, as a justification for war, is much more difficult to argue if you strike the first blow. The Israelis say their devastating pre-emptive strike on Iran is a special, truly existential, case. A regime, long committed to their destruction was, according to Israel, within weeks of developing nuclear weapons, just one of which could effectively wipe out their state and most of its citizens. How far does that justify the abandonment of diplomacy, the targeting of leaders, the collateral damage and death? And, by the way, why is it ok for some countries to have The Bomb- and not others?

Witnesses: Sir Richard Dalton, Jake Wallis Simons, Prof Mary Kaldor, Prof Ali Ansari

Panellists: Carmody Grey, Giles Fraser, Inaya Folarin-Iman , Mona Siddiqui

Presenter: Michael Buerk Producer: Catherine Murray Assistant Producer: Peter Everett Editor: Tim Pemberton