From Ukraine to the South China Sea, the past several years have reminded us that international peace and stability are not givens. The great issues of war and peace, order and disorder, are returning to the forefront of global affairs. My end-of-year reading list is thus made up of books that help us understand the causes and consequences of global upheaval -- and that underscore the exceptional role America has played in holding back the forces of chaos over the past 70 years.