The official naming of the conflict as “World War II” occurred in September 1945, shortly after the war ended, but the term had been in informal use for many years before that.
Long before the outbreak of hostilities in 1939, various writers and publications speculated about a second global conflict. For example, the Manchester Guardian used the phrase “World War No. 2” as early as 1919 to discuss a possible future war. Similarly, H.G. Wells referred to a “Second World War” in his 1930 novel The Autocracy of Mr Parham. These early usages framed the idea of a follow-up conflict after World War I. In the interwar period, newspapers in Thailand issued stories forecasting a second world war arising from rising tensions in Europe and Asia.
The term “World War II” gained traction even before the war officially started. A notable early reference appeared in a September 1939 Time Magazine issue, shortly after Germany invaded Poland, though exact confirmation is debated. Political Science Quarterly also used the phrase “Second World War” in 1942, reflecting growing acceptance. The phrase caught on quickly in Allied countries during the conflict. In the United Kingdom, it became common to refer to the conflict as either the “Second World War” or simply “World War Two.”
In Russia and many former Soviet states, the conflict is known by two related but distinct names. The entire conflict spanning from 1939 to 1945 is called the Second World War (Вторая мировая война). However, the period from the German invasion of the Soviet Union in 1941 to Germany’s surrender in 1945 is known domestically as the “Great Patriotic War” (Великая отечественная война), highlighting the specific national struggle within the broader global conflict.
While “World War I” had been called the “First World War” during and immediately after that conflict, there was no formal process originally to label the subsequent war. As World War II progressed, various names appeared in official and informal use. By mid-1945, as the war concluded, the United States War Department recognized the need for an official, uniform name for the conflict.
During the summer of 1945, the War Department aimed to standardize terminology to avoid confusion across documents and legislation. General North recommended selecting a clear official name to cover all theaters and the entire period of hostilities. After reviewing publications, radio broadcasts, and public laws, the Bureau of Public Relations confirmed that “World War II” was already broadly accepted by common usage in the United States. At least seven U.S. public laws used the term, strengthening its claim as the official title.
In September 1945, the Operations Division recommended formal designation of the conflict as “World War II”. The suggestion received concurrence from multiple military branches and was forwarded by the Joint Chiefs of Staff as a recommendation to President Harry S. Truman.
On September 10, 1945, Secretaries of War and Navy Henry L. Stimson and James Forrestal wrote to President Truman recommending that the term “World War II” be officially adopted as the name for the recent conflict. Truman approved the recommendation the very next day, September 11, 1945, marking the formal adoption of “World War II” in all U.S. official records and communications.
The official designation was published soon after in the Federal Register and reflected in War Department General Orders No. 80 on September 19, 1945. This order instructed that any official communication or publication refer to the conflict as “World War II,” standardizing the term across all U.S. military and governmental documents.
Thus, while the phrase “World War II” was in use throughout the war and even predates it in informal contexts, the official adoption in the United States came only after the war ended, with President Truman’s approval in September 1945. This formalization ensured clarity and uniformity in historical and legal records.
| Year | Event/Usage |
|---|---|
| 1919 | Manchester Guardian uses “World War No. 2” hypothetically. |
| 1930 | H.G. Wells publishes “Second World War” in a novel. |
| September 1939 | Time Magazine reportedly uses “World War II” early in the war. |
| Summer 1945 | U.S. War Department reviews need for official war name. |
| September 10, 1945 | Recommendation letter to President Truman for “World War II.” |
| September 11, 1945 | President Truman officially approves the name “World War II.” |
| September 19, 1945 | War Department General Orders formalize “World War II”. |
- The term “World War II” existed informally decades before WWII began.
- During the war, various names were used; “World War II” became increasingly common.
- The Soviet Union distinguishes the broader conflict from its own “Great Patriotic War.”
- The U.S. officially adopted “World War II” as the conflict’s name in September 1945.
- The formal declaration by President Truman standardized the term in all U.S. official documents.
