I think one thing writers can do is point out that you don't have to say openly racist things, like [Donald] Trump, to be a racist or a xenophobe.

The first World War in so many ways shaped the 20th century and really remade our world for the worse.

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.

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.

Many of the principle weapons that the Nazis used during World War II had their first trial in combat in Spain - the Messerschmitt 109 fighter plane for example, the Stuka dive bomber, the 88 millimeter artillery piece, which could be used both for antiaircraft purposes and also shelling on the ground. And American soldiers were the victims of these things in Spain, American volunteers. So this war was really a testing ground for Hitler. And he learned a great deal from it about the strengths and weaknesses of these different weapons.

Even [Ernst] Hemingway, perhaps the most intentionally non-political of American writers, became passionately partisan during the Spanish Civil War.

All of us living in today's world are facing an enormous crisis - arguably the greatest that humanity has ever faced - in the form of man-made global warming; one can't be neutral at such a moment. It's like claiming to be neutral if you're living in Germany in 1933.