Ketchum focuses largely on that story--how the United States dealt with its role in the world, or what exactly that role should be. These were years of intense debate, especially between isolationists and those who supported more active support for the Allies. Over time, the American people grew more supportive of intervention, but it took the shock of Pearl Harbor to draw the US into military involvement.
Ketchum covers the gamut of American life in these years--culture, politics, society. The book is part history, but it is also part memoir. We get a sense of what it was like to be a young person in this period, to be among those who would be called upon to serve. Ketchum was a member of the Yale class of 1943, and his descriptions of life on campus and of the debates going on there were excellent and shed a new and interesting light on events.
Highly recommended.
In a nutshell the book explains that Roosevelt and Churchill understood the Nazi threat like few others.