The story arc begins six months before Germany's invasion of Poland in September 1939 and ends shortly after the attack on Pearl Harbor on December 7, 1941, when the United States and, by extension, the Henry family, enters the war as well.

While the texts provide the reader with a German outlook on the war, Henry occasionally inserts notes as counterpoints to some of von Roon's statements.

During the voyage to Europe aboard SS Bremen, Victor befriends a British radio personality, Alistair Talcott "Talky" Tudsbury, his daughter, Pamela, and a German submarine officer, Commodore Grobke.

When the pact is made public, Pug's report draws him to the attention of President Roosevelt, who asks the Navy Commander to be his unofficial eyes and ears in Europe.

Although this new assignment again delays his desired sea command, it gives him the opportunity to travel to London, Rome, and Moscow where he meets Winston Churchill, Benito Mussolini, and Joseph Stalin in addition to Adolf Hitler, whom he met in Berlin.

After having finally obtained command of a battleship, USS California, he leaves for Pearl Harbor from Moscow, where he has discussed Lend-Lease issues and observed a battle.

In 1939 he accepts a job as a research assistant for an expatriate Jewish author, Aaron Jastrow, who is best known for his book A Jew's Jesus and lives in Siena, Italy.

Byron is three years younger than Natalie, but catches her attention by heroically saving her uncle from being trampled by a stampeding horse during the Palio, a festival in Siena.

When Natalie receives the proposal of marriage from Leslie that she has been eagerly awaiting, she realizes that the experience in Poland has changed her heart and that she is now in love with Byron.

Warren has graduated from Pensacola, married a Congressman's daughter, Janice Lacouture, and is assigned to USS Enterprise as a dive bomber pilot.

Wouk wrote that the novel was a traditional and linear narrative of the war that began with the cataclysmic event of Pearl Harbor, "Where we entered the ordeal that ended with our martial triumph, our temporary nuclear supremacy, and our global leadership that has since became our unwanted glory and our leaden burden.

[4][better source needed] The book was adapted in 1983 into a highly successful miniseries on the ABC television network, directed and produced by Dan Curtis.

Just as in the book, in addition to the lives of the Henry and Jastrow families, much time in the miniseries is devoted to the major global events of the early years of World War II.