At the beginning of June 1943, Linus Pauling Jr., the Paulings' eldest son, began the application process for a position in the U.S. Army Air Corps. He scored far above average in the mental tests and passed the physical examinations easily. By November, he had been accepted into the Air Corps Cadet Training School and was serving at Sheppard Field. His aspirations were dashed, however, when after only a month of training, an Army psychiatrist labeled him as susceptible to bouts of nervousness, thus rendering him ineligible for further cadet training. As a result, he was transferred to a non-officers group. Perpetually sick from the cold Texas nights, drafty living quarters, and poor diet, Linus Jr. began to consider transferring to the medical corps, where life for recruits was more comfortable.

Shortly after being removed from cadet school, Linus Jr. was transferred to radio training - a surprise because he had not initially qualified for work as a radioman. He spent the next several months learning the specifics of radio operation and repair. He found the work to be more engaging and the lifestyle more comfortable than that of his previous assignment. While many of his letters home detailed the quality of the social scene around the base, he occasionally sent notes to his father explaining the intricacies of his job.

Excepting the time that he spent at a few bleak Midwestern bases, Linus Jr. found himself experiencing some truly exciting locations. After he completed his training, he was shipped to New York City where he waited to begin service on an outbound ship. While there, he lived in an Army-requisitioned warehouse and spent his free hours exploring the city. Chicago and Boca Raton also featured into his travels and were made all the more interesting by a bevy of young women that he and his fellow military men encountered. During 1945, he served as a radioman on Army vessels traveling across the Atlantic to ports in Western Europe, Pakistan, and Egypt. While the time aboard the ship was often dull, the service gave Linus a chance to see parts of the world largely unvisited by Americans.

In April 1946, after 29 months in the service, Linus Jr. was honorably discharged from the United States military. He hitchhiked from the Bay Area to a family friend's home in Sacramento, eventually returning to Pasadena two years after his initial departure. He had grown during his service. He had learned a technical trade, tested himself physically, met many new people and seen sites beyond his safe California home. While the war made a painful impact on many American soldiers and families, it also introduced an entire generation to a world outside the U.S. borders - a place that was simultaneously terrifying and fascinating.