Atkinson begins by putting forth the underlying theme of the book: that the Allied North Africa campaign during World War II is a major pivot point, both in the fight against Axis powers and the United States' growth into a superpower. Next, he goes on to summarize the events of World War II leading up to the North Africa campaign. On September 1, 1939, Hitler launches an invasion of Poland. As allies to Poland, Great Britain and France declare war on Nazi Germany. In the summer of 1940, after months of fighting, the newly-installed French Prime Minister Philippe Petain agrees to an armistice with Hitler allowing France to control roughly the southern half of the country along with its North African colonies of Algeria, Tunisia, and Morocco. Known as Vichy France, the new state is expected to collaborate with Nazi Germany as well as its ally Italy, led by Prime Minister Benito Mussolini.

In 1941, two major events transform the course of the war. The first comes on June 22 when Nazi Germany and its Wehrmacht forces invade the Soviet Union, violating the two countries' non-aggression pact. The second comes on December 7 when Germany's ally Japan attacks a US naval base at Pearl Harbor outside Honolulu, Hawaii, killing over 2,000 Americans.