The alliance that failed to include Japan because of a two-front war fear

Ideas & Philosophy · Published 19 October 2026 · Updated 21 October 2026 Swipe more like this →

In short: In 1939, Germany and Italy forged a military pact intended to bind them so tightly that neither could seek peace without the other. But a secret geopolitical calculation—the fear of fighting on two fronts simultaneously—prevented a third major power from joining the agreement, fundamentally shaping the map of World War II.

The Pact of Steel, signed on May 22, 1939, by Joachim von Ribbentrop and Galeazzo Ciano, was designed as a military and political alliance between Germany and Italy. While it was originally envisioned as a tripartite agreement including Japan, the deal collapsed over strategic priorities. Japan sought a pact focused on the Soviet Union, whereas Italy and Germany were primarily concerned with the British Empire and France. Germany specifically feared that an alliance focused on the USSR would risk a two-front war before they could secure Western Europe.

The agreement was structured in two parts: an open declaration of cooperation and a "Secret Supplementary Protocol." The latter was particularly ambitious, urging a union of military and economic policies, as well as cooperation in press, news services, and propaganda to promote the Rome-Berlin Axis. It even required the placement of specialists in each other's capitals to ensure close liaison between the two nations' foreign ministers.

The pact was born from a complex shift in relations. Following World War I, where the two nations fought against each other, the Great Depression fueled the rise of Hitler and Mussolini. Despite early Italian opposition to German expansion into Austria, Italy's isolation following the Abyssinia Crisis eventually made a German alliance desirable. However, the pact's practical implementation was flawed; when Germany invaded Poland in 1939, Italy was unprepared and did not enter the war until June 1940.

The alliance effectively collapsed in 1943. Following the decisive defeat at the Second Battle of El Alamein and the Allied invasion of Sicily, Mussolini was overthrown. The new government signed an armistice with the Allies in September 1943, leaving Italy as a member of the pact in name only, despite the establishment of a Nazi-backed puppet government in the north.

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