Robert J. Bentley

If you start free trade with a Communist country, allow them to develop their own businesses, they don't remain communistic. They become a free society when they're able to make money themselves, and we increase trade with them and allow them to really produce products.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.