The Man in the High Castle by Philip K. Dick

Imagine the world if the Allies had lost the Second World War... Philip K Dick trips the switches of our minds with his vision of the world as it might have been: the African continent virtually wiped out, the Mediterranean drained to make farmland, the United States divided between the Japanese and the Nazis...In the neutral zone that divides the rival superpowers in America lives the author of an underground best-seller. His book - a rallying cry for all those who dream of overthrowing the occupiers - offers an alternative theory of world history. Does 'reality' lie with him, or is his world just one among many others?