Much like Munich in 1938, the Molotov-Ribbentrop Pact is often treated more as a rhetorical device than as a significant historical event. The discussion typically centres on two main narratives, neither of which is particularly illuminating: one insists that Stalin more or less triggered World War II, while the other contends that Western appeasement left Moscow with no choice and that the pact simply delayed conflict. So, let’s look at what the document says (WARNING: It’s old material I used for RWN. I edited it slightly to reduce bibliography-heaviness, but it might still not be very engaging).
- What did the pact actually do?
Signed on 23 August 1939, its secret protocol carved Eastern Europe into spheres of interest. Finland, Estonia and Latvia went to Moscow; Lithuania, at first, to Germany. Poland was split roughly along the Narew, Vistula and San, leaving the survival of any Polish state open. Germany also acknowledged Soviet interest in Bessarabia.
As it turns out, in 1939 EVERYONE was hedging. Poland had signed a non-aggression declaration with Germany in 1934 and took Teschen when Czechoslovakia was carved up in 1938. Hitler hoped to make Poland a junior partner against the USSR (see Rolf-Dieter Müller, Enemy in the East). When Warsaw refused his terms on Danzig, he ordered planning for an attack. The date: 3 April 1939, months before the pact signing.
Soviet Union had spent most of the 1930s as one of the most vocal advocates of a common front against Hitler: League membership in 1934, mutual assistance pacts with France and Czechoslovakia in 1935 (the Czech one binding only if France acted first). Paris never gave its pact a military convention, and London, wary of communism and doubtful of the Red Army after the purges, kept its distance. The Red Army could reach Czechoslovakia only through Poland or Romania, and neither would let it through. Historians still argue whether Stalin was ever fully committed to collective security or kept a German option open. But Munich, settled without Prague and without Moscow, gave him good reason to doubt the West.
The 1939 negotiations between Britain, France and the Soviet Union stalled for similar reasons. Warsaw refused to let Soviet troops in, while Moscow sought a free hand against what it called “indirect aggression” in the Baltic. Paris was keener on a deal than London, which showed little urgency: the Anglo-French military mission travelled to Moscow by sea (Chamberlain had flown to Hitler three times the previous September), and its British head had no written authority to sign anything. In May, Molotov replaced Litvinov, the main champion of collective security.
Meanwhile Estonia and Latvia, both under authoritarian regimes, signed non-aggression treaties with Germany, helping Hitler keep Soviet and British influence out of the region before his invasion of Poland. Estonia’s military leaders had intelligence ties with Berlin and hoped for German support against the USSR. A German report by Georg Dertinger described a secret Baltic understanding to consult Berlin on defence against the Soviet Union, with German help envisaged where necessary.
At this stage Germany could offer the Soviet Union what the West couldn’t or wouldn’t: neutrality, a territorial buffer, and a (shaky) ringside seat while the capitalist powers fought each other. The Red Army was also fighting Japan at Khalkhin Gol/Nomonhan. Stalin could have tried staying neutral without the deal, but how safe that would have been is another question. So he took the German offer.
- What happened after the treaty was signed?
By 17 September, when the Red Army invaded, the Wehrmacht had already inflicted a severe defeat on the Polish forces, though Warsaw resisted until the 28th. Stalin feared Germany might occupy the entire country, and Moscow justified its move by claiming to protect Ukrainians and Belarusians, who had indeed faced discrimination under Polish rule. Britain and France did not declare war on the USSR. Formally, the Anglo-Polish agreement limited British obligations to Germany. In practice, they could hardly have fought Germany and the Soviet Union at once, and after Poland fell there was little fighting on land in the West until spring 1940.
The treaty of 28 September fixed the border, moved Lithuania into the Soviet sphere in exchange for more Polish territory for Germany, and committed both sides to suppress Polish agitation against the other. Then each occupier remade its half. On the German side, tens of thousands of Poles, above all the educated elite, were shot in the first months, hundreds of thousands were expelled, and Jews were stripped of their rights and forced into ghettos: the first stage of what became full-scale genocide. On the Soviet side, the NKVD arrested officers, police, officials, landowners and clergy, moved hundreds of thousands of people to the Soviet interior in 1940–41, and in spring 1940 shot some 22,000 Polish officers and officials at Katyn and other sites.
Trade agreements came alongside the pact, in August 1939 and February 1940. Soviet oil, grain and raw materials went west; German machinery and military technology went east; Soviet transit routes helped Germany get around the British blockade. Berlin found the deal far less comfortable than it looks: Soviet demands competed with German rearmament, and Hitler disliked depending on Soviet supplies. The urge to seize Soviet resources fed into Barbarossa, though it can’t explain it alone.
- Did the pact cause the war?
No. Hitler decided to attack Poland well before signing the pact. The pact removed the immediate Soviet risk and made his timing much easier. Whether he would have struck without it, we can’t know. What turned a German-Polish war into a European one in September 1939 was Britain and France’s decision to stick to their guarantee to Poland. And the pact didn’t create Nazi expansionism: as we argued in the Radio War Nerd Munich series, Hitler and much of his military leadership wanted war sooner or later. Nor did it make Soviet expansion inevitable.
- Were the two regimes the same?
No. Both Germany and the Soviet Union were totalitarian states. But Stalin did not pursue the Nazis’ genocidal goals, and his ideology, however bloody and hostile to liberal democracy, was profoundly different from Nazism. By late 1939, about 1.5 million Jews, including refugees from German-occupied Poland, were under Soviet control. Many were killed after Germany invaded in 1941. But between 160,000 and 230,000 Polish Jews survived in the Soviet interior, having fled, been evacuated or been deported there. For some, Soviet action had the (sometimes unintended) effect of saving them from the Nazis. That doesn’t make the Soviet Union guiltless. The Winter War, mass deportations, Katyn and the annexation of the Baltic states all followed. In Stalin’s mind, security and expansion were never opposites.
- Did the pact buy the Soviet Union time?
Yes: nearly two years, and a frontier pushed west by 200–300 km in Poland and more in the Baltic. The new defences were unfinished, Soviet forces were packed too far forward, and they lost much of that depth within days in June 1941. Stalin had expected a long war in the West. France fell in six weeks, and he then read the German build-up as pressure ahead of negotiations, moving to full mobilisation way too late. But those gains still mattered.
The panzer spearheads reached the Dnieper within three weeks, but the infantry and horse-drawn supply columns needed to hold the ground had to cover the same distance on foot. That gap, German supply problems and ferocious Soviet resistance, above all around Smolensk, left Barbarossa badly behind schedule by the end of July.
- Was it a real alliance?
No. There was never a military alliance: no joint command, no common long-term strategy and, of course, no Soviet war on Britain or France. It was of course more than neutrality: a joint call for peace in September 1939, substantial trade, even the handover by the Soviets of some German and Austrian communist refugees to the Gestapo.
The relationship was tense from the beginning. After the Soviet Union invaded Finland in November 1939, Finland grew closer to Germany within a year and fought alongside it in 1941. The annexation of Bessarabia, which was recognized as a Soviet interest in the protocol, and northern Bukovina, which was not explicitly mentioned, brought Romania nearer to Berlin. In November 1940, Molotov visited Berlin to discuss joining the Tripartite Pact. Moscow’s tough demands (about Finland, Bulgaria, and the Turkish Straits) went unanswered, while Hitler had already ordered preparations in the East to continue regardless of the talks' outcome. The Barbarossa directive was issued in December, ironically followed by a new trade deal in January 1941. By then, both sides were mainly buying time.
- The bottom line
Great powers had long bargained at the expense of smaller nations, and they still do. A year earlier, at Munich, Britain and France had agreed to hand over the Sudetenland without consulting Prague. What set 1939 apart was how explicitly Berlin and Moscow divided Eastern Europe, and what followed on each side of the line.
The pact was neither the root cause of the war nor simply a Soviet land grab. It was a strategic arrangement between two vastly different regimes that, for a while, shared short-term interests while remaining mortal enemies. Stalin sought territory, depth and time, hoping Germany would exhaust itself in the West. Hitler gained a free hand against Poland, Soviet resources and temporary security in the east. Both gained, and both misjudged: Stalin misjudged Hitler’s timing, but Hitler misjudged the Soviet Union’s durability, which ultimately proved fatal for him.