Moscow, August 23, 1939. Europe had spent the summer preparing for war. German pressure on Poland was mounting, Britain and France had promised support to Warsaw, and diplomats were still trying to guess whether the Soviet Union would align against Adolf Hitler.
Then came the news from Moscow.
Nazi Germany and the Soviet Union—states whose political systems had spent years presenting one another as mortal enemies—had signed a non-aggression pact. German foreign minister Joachim von Ribbentrop and Soviet foreign minister Vyacheslav Molotov put their names to the agreement while Joseph Stalin looked on.
The public document promised that neither side would attack the other. A secret protocol went much further. It divided parts of eastern Europe into German and Soviet spheres of influence.
Nine days later, German forces invaded Poland.
Read the complete Today in History – August 23 edition.
Two Enemies Find a Temporary Use for Each Other
The agreement shocked much of Europe because Nazi Germany and the Soviet Union appeared ideologically incompatible. Hitler’s regime was violently anti-communist. Soviet propaganda had defined fascism as an existential enemy. Yet foreign policy in the summer of 1939 was driven by strategic calculations as much as ideology.
Hitler wanted to attack Poland without immediately facing a Soviet military response from the east. A deal with Moscow reduced the danger of a two-front war at the opening of the campaign.
Stalin had his own calculations. Negotiations with Britain and France had produced little confidence in a workable anti-German alliance. A pact with Berlin could buy the Soviet Union time, keep it temporarily outside a direct German war, and expand Soviet influence westward.
The Public Pact
The published treaty was short. Germany and the Soviet Union pledged not to attack one another, not to support a third power attacking the other signatory, and to settle disputes through consultation.
The treaty was to last ten years.
Read alone, it could be presented as a conventional diplomatic agreement between states seeking to avoid conflict. That was the version the public could see.
But another document existed beside it.
The Secret Protocol
The secret additional protocol assigned territories in eastern Europe to German or Soviet spheres of interest. Poland lay at the center of the arrangement, while the Baltic region, Finland and Bessarabia were also addressed.
This secret understanding transformed the pact from a promise of neutrality into an agreement about the political map of neighboring countries.
Its consequences became visible almost immediately. On September 1, 1939, Germany invaded Poland from the west. Britain and France declared war on Germany two days later. On September 17, Soviet forces entered eastern Poland.
Poland was defeated and partitioned between the two powers.
The Photograph Behind the Agreement
Images from Moscow show Ribbentrop, Molotov and Stalin in formal surroundings. The scene can look almost ordinary: officials, papers, handshakes, carefully arranged faces.
That visual calm is one reason the photographs remain so unsettling. The agreement was signed in a room while millions of people outside it had no say in the territorial decisions being made around them.
The featured photograph for this article is an authentic historical image connected to the pact, preserved through public archival collections. It should be read as evidence of a diplomatic moment—not as proof that the men pictured trusted one another.
September 1939: The Pact Becomes Geography
Once Germany invaded Poland, the diplomatic language of August became military reality. German armies advanced rapidly from the west and north. Soviet forces entered from the east more than two weeks later.
For Polish civilians and soldiers, the distinction between a public treaty and a secret protocol was no longer abstract. The country was occupied by two authoritarian powers whose security forces would impose radically different but devastating systems of repression.
Continue with our articles on Germany’s invasion of Poland on September 1, 1939 and the Soviet invasion on September 17.
An Agreement That Lasted Less Than Two Years
The non-aggression pact did not create a durable partnership. Germany and the Soviet Union cooperated when their interests overlapped, but suspicion remained fundamental.
On June 22, 1941, Hitler launched Operation Barbarossa and invaded the Soviet Union. The agreement signed in Moscow less than two years earlier collapsed under the largest land invasion in history.
That short lifespan does not reduce the pact’s importance. It helped make the opening of the European war possible under conditions Hitler considered favorable and shaped the fate of millions across eastern Europe.
Why August 23 Still Matters
August 23 is remembered not because diplomacy failed to prevent war, but because diplomacy itself became part of the mechanism that enabled conquest.
The Molotov–Ribbentrop Pact is a reminder that treaties should be judged by more than the reassuring language printed on their public pages. Power also operates through private assumptions, secret clauses and decisions made about people who are not present at the negotiating table.
It also explains why the first days of the Second World War cannot be understood solely as a German-Polish conflict. The political order of eastern Europe had already been discussed in Moscow before the first German units crossed the Polish frontier.
Continue Exploring August 23
This article is part of Today in History – August 23. Explore more major turning points in the Major Historical Events archive, or read the same day’s World War II story: the bombing of Stalingrad in 1942.
Sources & Historical Note
The public treaty text is available through Yale Law School’s Avalon Project. The United States Holocaust Memorial Museum provides context on the public pact, secret protocol and partition of Poland. The featured photograph is a public-domain archival image, not an AI reconstruction.
