President Franklin D. Roosevelt and Prime Minister Winston Churchill aboard the HMS Prince of Wales, August 14, 1941, working on the principles of fair dealing that became The Atlantic Charter. (ASSOCIATED PRESS/ASSOCIATED PRESS)

At the grand level of nations and continents, there was little to be explained. The great nations of Europe and Asia were locked up in mortal combat, and the greatest nation of all, the United States, with large interests in both continents, could not avoid involvement. Thus, following Pearl Harbor, the European war and the Asian war became World War II.

At the human level of personal actions and decisions, however, there was much to be explained. Franklin D. Roosevelt concluded long before Pearl Harbor that Germany and Japan constituted serious threats to the United States. Yet, realizing that his view was not generally shared by American voters, he charted a circuitous and sometimes duplicitous route to U.S. intervention in the wars those countries had started. Roosevelt’s indirection and delay spawned conspiracy theories while he lived and, after he died, a generation of U.S. policy based on a determination not to repeat what were seen as his mistakes. Historians still argue about Roosevelt’s timing and tactics, if not his results.

David Kaiser focuses on the critical months between May 1940 and December 1941. Others have written about this period, but few with his precision and insight. Kaiser spent decades teaching at the Naval War College, and he is especially informative on the interplay between productive capacity and strategic possibility in Roosevelt’s war plans. He makes a compelling case that a major reason Roosevelt did not go to war before 1941 was that America lacked the arms, ships and planes to do so effectively.

Yet politics was never far from Roosevelt’s mind. Kaiser necessarily cheats on the time limits he imposes on himself; his first chapter is labeled “May 1940” but is mostly devoted to the backstory essential to understanding how Roosevelt and America arrived at that fraught moment. Roosevelt in 1937 responded to Japanese aggression against China by proposing a “quarantine” of aggressors. The reaction to Roosevelt’s speech was less violently negative than Kaiser suggests, but it was cool enough that the president set aside any thoughts of confronting either the Japanese or the Germans. He walked softly ahead of the 1940 election, which, though less exciting than Kaiser asserts, made Roosevelt the world figure he became. He subsequently persuaded Congress to approve Lend-Lease aid to the countries fighting Germany and Japan, and he gradually maneuvered Tokyo and Berlin into deciding that war against the United States was inevitable. Shooting started on the Atlantic even before Pearl Harbor, and by mid-December 1941, Roosevelt had America in the wars he had long anticipated.

Partly, one supposes, because Kaiser cuts his story off at Pearl Harbor, he neglects to note one of the most important consequences of Roosevelt’s procrastination in taking America to war. Roosevelt had watched Woodrow Wilson take America to war in 1917, and he had watched America abandon Wilson soon after the war. Roosevelt realized that a president must not lead America to war but must be led to war by American public opinion. Following a meeting with members of Congress just after Pearl Harbor, in which Roosevelt had conspicuously not asked for a declaration of war, some of the lawmakers threatened to declare war even without a presidential request. This was exactly the emotional pitch Roosevelt had been aiming for. Though the costs of the war in blood and money rose appallingly during the next 31 / 2 years, Americans never doubted the necessity of the conflict. Nor have they ever yet doubted it. World War II remains the only truly “good war” in modern American history.

The front cover to "No End Save Victory: How FDR Led the Nation into War" by David Kaiser. (Basic Books/Basic Books)

For reasons best known to himself, Kaiser wraps his tightly told story in a nebulous theory of generations in American history. Again and again Roosevelt and his contemporaries are identified as members of the “Missionary” generation. Sociologists and some historians are drawn to this sort of analysis, but they largely waste their readers’ time. Generations make sense in relating the lives of single families, where predictable gaps separate parents from children. But generations make a muddle of understanding the lives of nations. Children are born every year, and to contend that a child born in 1946 has more in common with a child born in 1964, simply because both are classed as baby boomers, than he or she has with a child born in 1945 is nonsense. Kaiser undermines his analysis by pointing out how bitterly divided Roosevelt’s generation was over crucial matters of domestic and foreign policy. Class and even geography afford surer guides to thinking and action in the 1930s and ’40s than generations do.

Yet readers uninterested in theory can easily ignore this aspect of Kaiser’s tale. His thoroughly researched and well-informed narrative of what happened on the road to war makes the book fully worth the cover price.

Kaiser is a huge fan of Roosevelt. Repeatedly we hear of Roosevelt’s “brilliant leadership” and “extraordinary insight”; he was, Kaiser says, “the outstanding figure” of his generation. Fair enough; Kaiser, like everyone else, is entitled to his favorites. But one wonders how essential Roosevelt really was. It boggles the mind to imagine that America could have sat out the war; Wendell Willkie’s foreign policy platform in 1940 differed only marginally from Roosevelt’s. And it is difficult to see how the American side could have lost, given the productive resources of the nation. Details matter in history, and Kaiser is very good on details. But sometimes the big picture almost draws itself.

H.W. Brands is the author of “Traitor to His Class: The Privileged Life and Radical Presidency of Franklin Delano Roosevelt.” His biography of Ronald Reagan will be published next year.


How FDR Led the Nation Into War

By David Kaiser

Basic. 408 pp. $27.99