September 27, 1940

Tripartite Pact

Germany, Italy and Japan sign the Tripartite Pact

The treaty never named the United States, yet its key clause was carefully worded around a power not already fighting in either existing war.

27 September 1940: three signatures in Berlin

Representatives of Germany, Italy and Japan signed the Tripartite Pact in Berlin on 27 September 1940: Joachim von Ribbentrop for Germany, Galeazzo Ciano for Italy, and Saburō Kurusu, Japan's ambassador and special representative, for Japan. Hitler was present at the signing.

Japan recognised German and Italian leadership in establishing a "new order" in Europe, while Germany and Italy recognised Japanese leadership in establishing one in Greater East Asia.

Article 6 put the pact into force immediately upon signature, for a ten-year term.

What Article 3 actually promised

Article 3 promised political, economic and military assistance if a signatory was attacked by a power not then involved in the European war or the Sino-Japanese conflict. It was not an unconditional promise to join any war a signatory began.

Article 5 added that the pact did not alter any signatory's existing political relationship with the Soviet Union.

The United States is not named anywhere in the six-article text, but contemporary purpose and later historical analysis identify it as the principal deterrence target.

Technical commissions, but no integrated command

The pact formalised an alignment that already existed: Germany and Italy had signed the Pact of Steel in May 1939, and the Anti-Comintern Pact dated from 1936, with Italy joining in 1937.

It called for joint technical commissions to meet without delay, yet the three principal Axis states never developed institutions comparable to the Allies' integrated military and diplomatic coordination.

When Japan attacked Pearl Harbor, the pact's wording did not oblige Germany to enter the resulting war, because Japan was the attacker; the German declaration of 11 December 1941 went beyond what the treaty required.

Sources

Researched 23 Aug 2026 8 sources 2 audit passes

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