There are so many layers to 'The Years of Rice and Salt' that it's undoubtedly become one of the handful of books I shall return to, finding new connections and more discoveries in an evolving reader's interchange with an involving and immensely compassionate writer.
Why so many reviewers have labelled Robinson and reckon the novel is set to become one of the great classics of 21st-century science fiction escapes me. Such an enterprise simply cannot be pigeon-holed to the SF or even "alternative history" shelves of any library. It is great and — relatively — mainstream modern literature in any class.

'The Years of Rice and Salt' is a challenge to anybody who imagines that, say, a George Bush's simplistic, sublimely ignorant faith in US-style democracy and free market capitalism as models to be exported all around the planet, often enough through the barrel of a gun, is much more than a wretched, neo-imperialist insult to societies the remaining superpower would like to mould to its own convenience and interests.
If this book reminds me of any other, it's the magnificent 'Creation' (republished by Vintage Books), by an often far more openly political animal, Gore Vidal. He in the early 1980s crawled right inside the skin, not without humour, of a Persian who manages to meet and confront the views of the likes of Socrates, Confucius and the Buddha.

Some critics see weakness in the way Robinson's alternative vision of where humanity might be without Western civilisation sometimes closely parallels the history of our own. I consider these temporal bridges across from his world to the one we live in a strength of his writing, one manifestation of his skill in asking the reader to reconsider the all too familiar markers of our "progress" as a species from novel perspectives.
Bereft of such parallels, links and twists, Robinson's world would be "just" another piece of original fantasy writing, not what it is: a superbly polished and multi-faceted mirror casting back different lights on our contemporary cultures.
I hope I've managed to say one or two things others haven't yet. Often have I seen Robinson accused of being too didactic in his life's work, but it's precisely as a gentle and subtle teacher that he shines apart from other stars in modern writing.

I found patience with 'The Years of Rice and Salt' well rewarded by the fresh thought it stimulates on who constitutes the real terrorists and where the true horror stories are in these troubled times.

This is a slightly edited version of a piece just published at my place. Here, Chad Orzel reviewed the book a year back, finding Robinson a little over-optimistic.