As usual, Kagan’s writing bristles with insights and ideas. His latest book aims to counter the view of many liberal internationalists that because the United States seeks a liberal order it must eschew traditional great-power diplomacy and power projection. Kagan believes in the value of a liberal, democratic world order and fears that anarchy and chaos will result if this order breaks down. But he argues that the order rests on U.S. military and economic power rather than on the respect that other powers have for noble American ideals. He points out that the United States has often been most successful internationally under leaders who were not particularly beloved by the rest of the world, such as Richard Nixon. In contrast, Woodrow Wilson was greeted by huge and enthusiastic crowds across Europe after World War I but was unable to capitalize on his unprecedented soft power. From Kagan’s point of view, the way to preserve a U.S.-led liberal world order is to tend to the foundations of American power at home and to project that power abroad in a thoughtful and confident manner.