Does McCain ever lose a night's sleep over war?
John McCain, we all know, after being shot out of the sky, was captured by the North Vietnamese, imprisoned and tortured. We know that few of us would have had the guts or tenacity to put up for so long with his trials of pain and sorrows.
But do we know - for the journalists have failed to ask and he has omitted to mention - who he killed from the sky, how many, and how does he feel about that deep inside when he has to reflect alone and make his peace with God?
These conundrums don't seem to weigh a tenth of an ounce in the American election. But they should. How we treat other lives is surely the supreme test of a civilisation.
Tolstoy's Prince Andrew, one of the central characters of War and Peace, thought he had the answer: 'Drain all the blood out of men's veins and fill them up with water, and then there'll be no more war. Women's talk. Women's talk.'
But the real issue, as Tolstoy posed later in his magnificent book, is this: 'It is beyond our comprehension that millions of Christian men and women should have killed and tortured each other just because Napoleon was a megalomaniac, Alexander [the Russian tsar] was obstinate, the English were devious and the Duke of Oldenburg was badly done by ... War is the vilest thing in human life and we aught to understand that and not play at war ... Otherwise war will be a nice hobby for idle people and butterfly minds ... The military class get all the honours. It's still the highest class, universally respected. The biggest rewards go to the man who killed the most people ... How can God look down from heaven and listen to it all?'
I would like to ask Senator McCain if, like the navigator of the Enola Gay, the plane that dropped the atomic bomb on Hiroshima, he ever came off a mission 'had a bite and a few beers, and hit the sack, and had not lost a night's sleep over the bomb in 40 years'.
But why should I single out Senator McCain? Sometime or other, perhaps most of us have bought a cinema ticket to see artfully performed, urgently fascinating, grisly and gruesome carnage.
For the more cerebral, there is the tingling sense of shared heroism as we read the poems of Wilfrid Owen, Sigfried Sassoon and Edmund Blunden. As Joanna Bourke has written, they are 'high diction with its stock phrases - 'baptism of fire', 'transfigured youth' and 'gallant warriors'.'
In the hands of talented filmmakers, poets and writers - and journalists, too - war comes to resemble sport, the most exciting game in existence which, by pushing men to their physical and emotional limits, provides deep satisfaction for onlookers and survivors.
I don't know Barack Obama's deep convictions on the matter of war - and he has said some stupid things, like being prepared to bomb Pakistan - but I get the sense from his books and his tone that, in most cases, it is a horror to be avoided.
He has had the chance to study Senator McCain close up. On this issue of mass killing, I hope he has drawn the only lesson a questioning and moral man can.
Jonathan Power is a London-based journalist