We know from history that assassinations can have limitless effects. And when the President of the United States orders the state murder (for this, alas, is what it was) of an Iranian general, it is hard to see a good end.

There will be retaliation. Other countries will be drawn in. Our own ability to make moral objections to such acts is gravely weakened because Donald Trump's action lies miles outside the laws of civilised war. Iran has no long-range drones (as far as we know), but can you begin to imagine the justified rage in the USA if a senior American general were shot dead on the steps of the Pentagon by an Iranian hit team? Yet what, in the end, would be the moral difference between the two acts? Now we can only tremble at what might come next.