On December 6, 1941, John Paul Stevens enlisted in the U.S. Navy. One day later, Japan attacked Pearl Harbor, drawing the United States into World War II. Stevens would spend the war working in Pacific intelligence, contributing to a codebreaking effort that helped American forces find and shoot down the aircraft carrying Admiral Isoroku Yamamoto, the architect of the attack.

The Chicago native’s wartime service preceded a legal career that ultimately brought him to the U.S. Supreme Court. He earned a Bronze Star for his work in the Navy. Decades later, he would point to the targeting of Yamamoto as an experience that planted his first doubts about the death penalty.

Stevens was part of a team that decrypted Japanese radio traffic. That intelligence helped American pilots locate Yamamoto’s plane and shoot it down. The mission targeted a single named enemy commander, a distinction Stevens later recalled when discussing his thinking about capital punishment.

His reflection linked two very different settings: a wartime operation against a senior military figure and the legal system’s authority to impose a death sentence. Stevens said the targeted killing had sown his initial doubts about the death penalty, long before he became a Supreme Court justice.

The future justice also distinguished himself academically. A Chicago native, he finished first in his class at Northwestern law. His path from naval intelligence to the nation’s highest court made his wartime experience part of the personal history he brought to judicial questions.

Stevens’ story is a reminder, on Veterans Day, of the less visible work undertaken during the war. His role was not in the cockpit of the aircraft that intercepted Yamamoto, but in the codebreaking effort that helped make the mission possible.