It was a perfect spring day in Hiroshima last week. I was there for my 25th wedding anniversary, which may sound odd, but my wife and I both work on Foyle’s War, which is now set in the atomic age, so it seemed appropriate. We strolled together around the A-Bomb Dome, the twisted, iconic ruin that is all that is left of the old city, then entered the Peace Memorial Museum, built in 1955, the year I was born. I found the whole experience incredibly moving: the child’s bike dug out of the ruins, the watch that had stopped at 8.15, the piece of wall that still carries the ‘ghost’ of the man who was sitting against it when the bomb fell. I was rather surprised to come away with the view that we should abandon our nuclear deterrent not because it is too expensive or irrelevant, as I used to believe, but simply because the ownership of such a monstrous weapon diminishes us.