World War II is understandably an attractive point of divergence for writers of alternative history. "What if the Nazis won?" is a compelling question that has been explored many times over. Dominion takes a slightly different tack, imagining instead that the war itself was largely averted through appeasement. C.J. Sansom takes as his point of divergence the fateful meeting in which Churchill, Halifax, and Chamberlain decide who will succeed the latter as Prime Minister. In …