Someday, I have no doubt, the dead from today's wars will be seen with a similar sense of sorrow at needless loss and folly as those millions of men who lie in the cemeteries of France and Belgium - and tens of millions of Americans will feel a similar revulsion for the politicians and generals who were so spendthrift with others' lives.

One of my favourite contemporary fiction writers is a Texan, Ben Fountain. His extraordinary novel, Billy Lynn's Long Half-Time Walk, all takes place within the half-time show at a Dallas Cowboys football game. No one has better summed up the American appetite for spectacle, the link between sports and politics, and the absolute madness of George W. Bush's Iraq War.

I think writers can respond by writing about the refugee crisis, by looking at problems faced by migrants, by trying hard to portray them as the human beings that they are.

I can certainly sympathize with writers who don't want to put themselves or their loved ones at risk.

In his fierce, bold determination to see the lives of modern-day slaves up close, Benjamin Skinner reminds me of the British abolitionist of two hundred years ago, Zachary Macaulay, who once traveled on a slave ship across the Atlantic, taking notes. Skinner goes everywhere, from border crossings to brothels to bargaining sessions with dealers in human beings, to bring us this vivid, searing account of the wide network of human trafficking and servitude which spans today's globe.

You know, by 1936, Hitler was already talking very loudly about his desire to expand to the east. Mussolini, in 1935, went and then in the next year, conquered Ethiopia, acquiring himself a colony. So people at the time really saw fascism not just as an evil but as an aggressive evil that seemed to be spreading.

Some 2,800 Americans went to Spain [during the Spanish Civil War], and it was, by far, the largest number of Americans before or since who've ever joined somebody else's civil war. I think they were primarily people who were deeply alarmed by the menace of fascism. They saw this on the horizon. I quote one volunteer, Maury Colow of New York, who said, "for us it was never Franco, it was always Hitler."