The Molotov–Ribbentrop Pact, named after the Soviet foreign minister Vyacheslav Molotov and the German foreign minister Joachim von Ribbentrop, officially the Treaty of Non-Aggression between Germany and the Soviet Union, and also known as the Ribbentrop–Molotov Pact or Nazi–Soviet Pact, was a non-aggression pact signed in Moscow in the late hours of 23 August 1939.
The Pact assured a non-involvement of the Soviet Union in a European War, as well as separating Germany and Japan from forming a military alliance, thus allowing Stalin to concentrate on Japan in the battles of Khalkhin Gol (Nomonhan). The pact remained in effect until 22 June 1941, when Germany invaded the Soviet Union.
In addition to stipulations of non-aggression, the treaty included a secret protocol that divided territories of Romania, Poland, Lithuania, Latvia, Estonia and Finland into Nazi and Soviet "spheres of influence", anticipating potential "territorial and political rearrangements" of these countries. Thereafter, Germany invaded Poland on September 1, 1939. The Soviet Union would not invade Poland until the Nomonhan incident was officially concluded by the Molotov-Togo agreement, which it was on 15 September 1939, taking effect on 16 September, at which time Stalin ordered Soviet forces to invade Poland on 17 September 1939. Part of southeastern (Karelia) and Salla region Finland was annexed by the Soviet Union after the Winter War. This was followed by Soviet annexations of Estonia, Latvia, Lithuania, Bessarabia, Northern Bukovina and the Hertza region.
Of the territories of Poland annexed by the Soviet Union between 1939 and 1940, the region around Bialystok and a minor part of Galicia east of the San river around Przemysl were the only ones returned to the Polish state at the end of World War II. Of all other territories annexed by the USSR in 1939-40, the ones detached from Finland (Karelia, Petsamo), Estonia (Ingrian area and Petseri County) and Latvia (Abrene) remained part of the Russian Federation, the successor state of the Soviet Union, after 1991. 
The Molotov–Ribbentrop Pact is commonly referred to under a number of names in addition to the official one and the one bearing the names of the foreign ministers. It is also known as the Nazi–Soviet Pact, Hitler–Stalin Pact, German–Soviet Non-aggression Pact and sometimes the Nazi–Soviet Alliance or Communazi Pact
The outcome of the First World War was disastrous for both the German Reich and the Russian Soviet Federative Socialist Republic. During the war, the Bolsheviks struggled for survival, and Vladimir Lenin had no option except to recognize the independence of Finland, Estonia, Latvia, Lithuania and Poland. Moreover, facing a German military advance, Lenin and Trotsky were forced to enter into the Treaty of Brest-Litovsk, which ceded massive western Russian territories to the German Empire. After Germany's collapse, a multinational Allied-led army intervened in the Russian Civil War (1917-1922).
On 16 April 1922, Germany and the Soviet Union entered the Treaty of Rapallo, pursuant to which they renounced territorial and financial claims against each other. The parties further pledged neutrality in the event of an attack against one another with the 1926 Treaty of Berlin. While trade between the two countries fell sharply after World War I, trade agreements signed in the mid-1920s helped to increase trade to 433 million Reichsmarks per year by 1927.
At the beginning of the 1930s, the Nazi Party's rise to power increased tensions between Germany and the Soviet Union along with other countries with ethnic Slavs, who were considered "Untermenschen" (inferior) according to Nazi racial ideology. Moreover, the anti-Semitic Nazis associated ethnic Jews with both communism and financial capitalism, both of which they opposed. Consequently, Nazi theory held that Slavs in the Soviet Union were being ruled by "Jewish Bolshevik" masters. In 1934, Hitler himself had spoken of an inescapable battle against both Pan-Slavism and Neo-Slavism, the victory in which would lead to "permanent mastery of the world", though he stated that they would "walk part of the road with the Russians, if that will help us." The resulting manifestation of German anti-Bolshevism and an increase in Soviet foreign debts caused German–Soviet trade to dramatically decline. Imports of Soviet goods to Germany fell to 223 million Reichsmarks in 1934 as the more isolationist Stalinist regime asserted power and the abandonment of post–World War I Treaty of Versailles military controls decreased Germany's reliance on Soviet imports.
In 1936, Germany and Fascist Italy supported Spanish Nationalists in the Spanish Civil War, while the Soviets supported the partially socialist-led Second Spanish Republic under the leadership of president Manuel Azaña. Thus, in a sense, the Spanish Civil War became also the scene of a proxy war between Germany and the USSR. In 1936, Germany and Japan entered the Anti-Comintern Pact, and were joined a year later by Italy.
Hitler's fierce anti-Soviet rhetoric was one of the reasons why the UK and France decided that Soviet participation in the 1938 Munich Conference regarding Czechoslovakia would be both dangerous and useless. The Munich Agreement that followed marked a partial German annexation of Czechoslovakia in late 1938 followed by its complete dissolution in March 1939, which as part of the appeasement of Germany conducted by Chamberlain's and Daladier's cabinets. This policy immediately raised the question of whether the Soviet Union could avoid being next on Hitler's list. The Soviet leadership believed that the West wanted to encourage German aggression in the East and that France and Britain might stay neutral in a war initiated by Germany, hoping that the warring states would wear each other out and put an end to both the Soviet Union and Nazi Germany.
For Germany, because an autarkic economic approach or an alliance with Britain were impossible, closer relations with the Soviet Union to obtain raw materials became necessary, if not just for economic reasons alone. Moreover, an expected British blockade in the event of war would create massive shortages for Germany in a number of key raw materials. After the Munich agreement, the resulting increase in German military supply needs and Soviet demands for military machinery, talks between the two countries occurred from late 1938 to March 1939. The third Soviet Five Year Plan required massive new infusions of technology and industrial equipment. German war planners had estimated massive raw materials shortfalls if Germany entered a war without Soviet supply.
On 31 March 1939, in response to Nazi Germany's defiance of the Munich Agreement and occupation of Czechoslovakia, the United Kingdom pledged the support of itself and France to guarantee the independence of Poland, Belgium, Romania, Greece, and Turkey. On 6 April Poland and the UK agreed to formalize the guarantee as a military alliance, pending negotiations. On 28 April, Hitler denounced the 1934 German–Polish Non-Aggression Pact and the 1935 Anglo-German Naval Agreement.
Starting in mid-March 1939, in attempts to contain Hitler's expansionism, the Soviet Union, Britain and France traded a flurry of suggestions and counterplans regarding a potential political and military agreement. Although informal consultations commenced in April, the main negotiations began only in May. At the same time, throughout early 1939, Germany had secretly hinted to Soviet diplomats that it could offer better terms for a political agreement than Britain and France.
The Soviet Union feared Western powers and the possibility of "capitalist encirclements", had little faith either that war could be avoided, or faith in the Polish army, and wanted nothing less than an ironclad military alliance with France and Britain that would provide a guaranteed support for a two-pronged attack on Germany. Britain and France believed that war could still be avoided, and that the Soviet Union, weakened by the Great Purge, could not be a main military participant, a point that many military sources were at variance with, especially after the sound thrashing administered to the Japanese Kwantung army on the Manchurian frontier. France was more anxious to find an agreement with the USSR than was Britain; as a continental power, it was more willing to make concessions, more fearful of the dangers of an agreement between the USSR and Germany These contrasting attitudes partly explain why the USSR has often been charged with playing a double game in 1939: carrying on open negotiations for an alliance with Britain and France while secretly considering propositions from Germany.
By the end of May drafts were formally presented. In mid-June the main Tripartite negotiations started. The discussion was focused on potential guarantees to central and east European countries should a German aggression arise. The USSR proposed to consider that a political turn towards Germany by the Baltic states would constitute an "indirect aggression" towards the Soviet Union. Britain opposed such proposals, because they feared the Soviets' proposed language could justify a Soviet intervention in Finland and the Baltic states, or push those countries to seek closer relations with Germany. The discussion about a definition of "indirect aggression" became one of the sticking points between the parties, and by mid-July the tripartite political negotiations effectively stalled, while the parties agreed to start negotiations on a military agreement, which the Soviets insisted must be entered into simultaneously with any political agreement.
Beginning of Soviet–German secret talks
From April–July, Soviet and German officials made statements regarding the potential for the beginning of political negotiations, while no actual negotiations took place during that time period. The ensuing discussion of a potential political deal between Germany and the Soviet Union had to be channeled into the framework of economic negotiations between the two countries, because close military and diplomatic connections, as was the case before mid-1930s, had afterward been largely severed. In May, Stalin replaced his Foreign Minister Maxim Litvinov, who was regarded as pro-western and who was also Jewish, with Vyacheslav Molotov, allowing the Soviet Union more latitude in discussions with more parties, not only with Britain and France.
In late July and early August 1939, Soviet and German officials agreed on most of the details for a planned economic agreement, and specifically addressed a potential political agreement, which the Soviets stated could only come after an economic agreement.
In early August, Germany and the Soviet Union worked out the last details of their economic deal, and started to discuss a political alliance. They explained to each other the reasons for their foreign policy hostility in the 1930s, finding common ground in the anti-capitalism of both countries.
At the same time, British, French and Soviet negotiators scheduled three-party talks on military matters to occur in Moscow in August 1939, aiming to define what the agreement would specify should be the reaction of the three powers to a German attack. The tripartite military talks, started in mid-August, hit a sticking point regarding passage of Soviet troops through Poland if Germans attacked, and the parties waited as British and French officials overseas pressured Polish officials to agree to such terms. Polish officials refused to allow Soviet troops on to Polish territory if Germany attacked; as Polish foreign minister Józef Beck pointed out, they feared that once the Red Army entered their territories, it might never leave.
On August 19, the 1939 German–Soviet Commercial Agreement was finally signed. On 21 August the Soviets suspended Tripartite military talks, citing other reasons. That same day, Stalin received assurance that Germany would approve secret protocols to the proposed non-aggression pact that would place half of Poland (border along the Vistula river), Latvia, Estonia, Finland, and Bessarabia in the Soviets' sphere of influence. That night, Stalin replied that the Soviets were willing to sign the pact, and that he would receive Ribbentrop on 23 August.
The secret protocol
'Following completion of the Soviet–German trade and credit agreement, there has arisen the question of improving political links between Germany and the USSR.
On 22 August, one day after the talks broke down with France and Britain, Moscow revealed that Ribbentrop would visit Stalin the next day. This happened while the Soviets were still negotiating with the British and French missions in Moscow. With the Western nations unwilling to accede to Soviet demands, Stalin instead entered a secret Nazi–Soviet alliance. On 24 August a 10-year non-aggression pact was signed with provisions that included: consultation; arbitration if either party disagreed; neutrality if either went to war against a third power; no membership of a group "which is directly or indirectly aimed at the other."
Most notably, there was also a secret protocol to the pact, revealed only after Germany's defeat in 1945, according to which Romania, Poland, Lithuania, Latvia, Estonia and Finland were divided into German and Soviet "spheres of influence". In the north, Finland, Estonia and Latvia were assigned to the Soviet sphere. Poland was to be partitioned in the event of its "political rearrangement"—the areas east of the Pisa, Narev, Vistula and San rivers going to the Soviet Union while Germany would occupy the west. Lithuania, adjacent to East Prussia, would be in the German sphere of influence, although a second secret protocol agreed to in September 1939 reassigned the majority of Lithuania to the USSR. According to the secret protocol, Lithuania would be granted the city of Vilnius – its historical capital, which was under Polish control during the inter-war period. Another clause of the treaty was that Germany would not interfere with the Soviet Union's actions towards Bessarabia, then part of Romania; as the result, Bessarabia was joined to the Moldovan ASSR, and become the Moldovan SSR under control of Moscow. 
At the signing, Ribbentrop and Stalin enjoyed warm conversations, exchanged toasts and further addressed the prior hostilities between the countries in the 1930s. They characterized Britain as always attempting to disrupt Soviet–German relations, stated that the Anti-Comintern pact was not aimed at the Soviet Union, but actually aimed at Western democracies and "frightened principally the City of London [i.e., the British financiers] and the English shopkeepers."
On 24 August, Pravda and Izvestia carried news of the non-secret portions of the Pact, complete with the now infamous front-page picture of Molotov signing the treaty, with a smiling Stalin looking on (at the top of this article). The news were met with utter shock and surprise by government leaders and media worldwide, most of whom were aware only of the British–French–Soviet negotiations that had taken place for months. The Molotov–Ribbentrop Pact was received with shock by Nazi Germany's allies, notably Japan, by the Comintern and foreign communist parties, and by Jewish communities all around the world. So, that day, German diplomat Hans von Herwarth, whose grandmother was Jewish, informed Guido Relli, an Italian diplomat, and American chargé d'affaires Charles Bohlen on the secret protocol regarding vital interests in the countries' allotted "spheres of influence", without revealing the annexation rights for "territorial and political rearrangement".
Time Magazine repeatedly referred to the Pact as the "Communazi Pact" and its participants as "communazis" until April 1941.
Soviet propaganda and representatives went to great lengths to minimize the importance of the fact that they had opposed and fought against the Nazis in various ways for a decade prior to signing the Pact. Upon signing the pact, Molotov tried to reassure the Germans of his good intentions by commenting to journalists that "fascism is a matter of taste". For its part, Nazi Germany also did a public volte-face regarding its virulent opposition to the Soviet Union, though Hitler still viewed an attack on the Soviet Union as "inevitable".
Concerns over the possible existence of a secret protocol were first expressed by the intelligence organizations of the Baltic states scant days after the pact was signed. Speculation grew stronger when Soviet negotiators referred to its content during negotiations for military bases in those countries (see occupation of the Baltic States).
The day after the Pact was signed, the French and British military negotiation delegation urgently requested a meeting with Soviet military negotiator Kliment Voroshilov. On August 25, Voroshilov told them "[i]n view of the changed political situation, no useful purpose can be served in continuing the conversation." That day, Hitler told the British ambassador to Berlin that the pact with the Soviets prevented Germany from facing a two front war, changing the strategic situation from that in World War I, and that Britain should accept his demands regarding Poland.
On 25 August, surprising Hitler, Britain entered into a defense pact with Poland. Consequently, Hitler postponed his planned 26 August invasion of Poland to 1 September. Britain and France responded by guaranteeing the sovereignty of Poland, so they declared war on Germany on 3 September.
Further secret protocol modifications,
On 10 January 1941, Germany and the Soviet Union signed an agreement settling several ongoing issues. Secret protocols in the new agreement modified the "Secret Additional Protocols" of the German–Soviet Boundary and Friendship Treaty, ceding the Lithuanian Strip to the Soviet Union in exchange for 7.5 million dollars (31.5 million Reichsmark). The agreement formally set the border between Germany and the Soviet Union between the Igorka river and the Baltic Sea. It also extended trade regulation of the 1940 German–Soviet Commercial Agreement until August 1, 1942, increased deliveries above the levels of year one of that agreement, settled trading rights in the Baltics and Bessarabia, calculated the compensation for German property interests in the Baltic States now occupied by the Soviets and other issues. It also covered the migration to Germany within two and a half months of ethnic Germans and German citizens in Soviet-held Baltic territories, and the migration to the Soviet Union of Baltic and "White Russian" "nationals" in German-held territories.
Early political issues
Before the pact's announcement, Communists in the West denied that such a treaty would be signed. Future member of the Hollywood Ten Herbert Biberman denounced rumors as "Fascist propaganda". Earl Browder, head of the Communist Party USA, stated that "there is as much chance of agreement as of Earl Browder being elected president of the Chamber of Commerce." Beginning in September 1939, the Soviet Comintern suspended all anti-Nazi and anti-fascist propaganda, explaining that the war in Europe was a matter of capitalist states attacking each other for imperialist purposes. Western Communists acted accordingly; while before they supported protecting collective security, now they denounced Britain and France going to war.
When anti-German demonstrations erupted in Prague, Czechoslovakia, the Comintern ordered the Czech Communist Party to employ all of its strength to paralyze "chauvinist elements." Moscow soon forced the Communist Parties of France and Great Britain to adopt an anti-war position. On 7 September, Stalin called Georgi Dimitrov, and the latter sketched a new Comintern line on the war. The new line—which stated that the war was unjust and imperialist—was approved by the secretariat of the Communist International on 9 September. Thus, the various western Communist parties now had to oppose the war, and to vote against war credits. Although the French Communists had unanimously voted in Parliament for war credits on 2 September and on 19 September declared their "unshakeable will" to defend the country, on 27 September the Comintern formally instructed the party to condemn the war as imperialist. By 1 October the French Communists advocated listening to German peace proposals, and Communist leader Maurice Thorez deserted from the French Army on 4 October and fled to Russia. Other Communists also deserted from the army.
The Communist Party of Germany featured similar attitudes. In Die Welt, a communist newspaper published in Stockholm the exiled communist leader Walter Ulbricht opposed the allies (Britain representing "the most reactionary force in the world") and argued: "The German government declared itself ready for friendly relations with the Soviet Union, whereas the English–French war bloc desires a war against the socialist Soviet Union. The Soviet people and the working people of Germany have an interest in preventing the English war plan." 
Despite a warming by the Comintern, German tensions were raised when the Soviets stated in September that they must enter Poland to "protect" their ethnic Ukrainian and Belorussian brethren therein from Germany, though Molotov later admitted to German officials that this excuse was necessary because the Soviets could find no other pretext for the Soviet invasion.
While active collaboration between Nazi Germany and Soviet Union caused great shock in western Europe and amongst communists opposed to Germany, on 1 October 1939, Winston Churchill declared that the Russian armies acted for the safety of Russia against "the Nazi menace."
When a joint German–Soviet peace initiative was rejected by Britain and France on 28 September 1939, Soviet foreign policy became critical of the Allies and more pro-German in turn. During the fifth session of the Supreme Soviet on 31 October 1939 Molotov analysed the international situation thus giving the direction for Communist propaganda. According to Molotov Germany had a legitimate interest in regaining its position as a great power and the Allies had started an aggressive war in order to maintain the Versailles system.
Molotov declared in his report entitled "On the Foreign Policy of the Soviet Union" (31 October 1939) held on the fifth (extraordinary) session of the Supreme Soviet, that the Western "ruling circles" disguise their intentions with the pretext of defending democracy against Hitlerism, declaring "their aim in war with Germany is nothing more, nothing less than extermination of Hitlerism. [...] There is absolutely no justification for this kind of war. The ideology of Hitlerism, just like any other ideological system, can be accepted or rejected, this is a matter of political views. But everyone grasps, that an ideology can not be exterminated by force, must not be finished off with a war."
Denial of the Secret Protocol's by the Soviet Union
The German original of the secret protocols was presumably destroyed in the bombing of Germany, but in late 1943, Ribbentrop had ordered that the most secret records of the German Foreign Office from 1933 on, amounting to some 9,800 pages, be microfilmed. When the various departments of the Foreign Office in Berlin were evacuated to Thuringia at the end of the war, Karl von Loesch, a civil servant who had worked for the chief interpreter Paul Otto Schmidt, was entrusted with these microfilm copies. He eventually received orders to destroy the secret documents but decided to bury the metal container with the microfilms as a personal insurance for his future well-being. In May 1945, von Loesch approached the British Lt. Col. Robert C. Thomson with the request to transmit a personal letter to Duncan Sandys, Churchill's son-in-law. In the letter, von Loesch revealed that he had knowledge of the documents' whereabouts but expected preferential treatment in return. Colonel Thomson and his American counterpart Ralph Collins agreed to transfer von Loesch to Marburg in the American zone if he would produce the microfilms. The microfilms contained a copy of the Non-Aggression Treaty as well as the Secret Protocol. Both documents were discovered as part of the microfilmed records in August 1945 by the State Department employee Wendell B. Blancke, head of a special unit called "Exploitation German Archives" (EGA). 
The treaty was published in the United States for the first time by the St. Louis Post-Dispatch on May 22, 1946, in Britain by the Manchester Guardian. It was also part of an official State Department publication, Nazi–Soviet Relations 1939–1941, edited by Raymond J. Sontag and James S. Beddie in January 1948. The decision to publish the key documents on German–Soviet relations, including the treaty and protocol, had been taken already in spring 1947. Sontag and Beddie prepared the collection throughout the summer of 1947. In November 1947, President Truman personally approved the publication but it was held back in view of the Foreign Ministers Conference in London scheduled for December. Since negotiations at that conference did not prove constructive from an American point of view, the document edition was sent to press. The documents made headlines worldwide. State Department officials counted it as a success: "The Soviet Government was caught flat-footed in what was the first effective blow from our side in a clear-cut propaganda war."
Despite publication of the recovered copy in western media, for decades, it was the official policy of the Soviet Union to deny the existence of the secret protocol. The secret protocol's existence was officially denied until 1989. Vyacheslav Molotov, one of the signatories, went to his grave categorically rejecting its existence. The French Communist Party did not acknowledge the existence of the secret protocol until 1968, as the party de-Stalinized.
On 23 August 1986, tens of thousands of demonstrators in 21 western cities including New York, London, Stockholm, Toronto, Seattle, and Perth participated in Black Ribbon Day Rallies to draw attention to the secret protocols.
Stalin's Falsifiers of History and Axis negotiations
In response to the publication of the secret protocols and other secret German–Soviet relations documents in the State Department edition Nazi–Soviet Relations (1948), Stalin published Falsifiers of History, which included the claim that, during the Pact's operation, Stalin rejected Hitler's claim to share in a division of the world, without mentioning the Soviet offer to join the Axis. That version persisted, without exception, in historical studies, official accounts, memoirs and textbooks published in the Soviet Union until the Soviet Union's dissolution.
The book also claimed that the Munich agreement was a "secret agreement" between Germany and "the west" and a "highly important phase in their policy aimed at goading the Hitlerite aggressors against the Soviet Union."
Denunciation of the pact
For decades, it was the official policy of the Soviet Union to deny the existence of the secret protocol to the Soviet–German Pact. It was only after the Baltic  Way demonstrations of 23 August 1989, where two million people created a human chain set on the 50th anniversary of the signing of the Pact that this policy changed. At the behest of Mikhail Gorbachev, Alexander Nikolaevich Yakovlev headed a commission investigating the existence of such a protocol.
In December 1989, the commission concluded that the protocol had existed and revealed its findings to the Congress of People's Deputies of the Soviet Union. As a result, the first democratically elected Congress of Soviets passed the declaration confirming the existence of the secret protocols, condemning and denouncing them. Both successor-states of the pact parties have declared the secret protocols to be invalid from the moment they were signed. The Federal Republic of Germany declared this on September 1, 1989 and the Soviet Union on December 24, 1989, following an examination of the microfilmed copy of the German originals.
The Soviet copy of the original document was declassified in 1992 and published in a scientific journal in early 1993.
In August 2009, in an article written for the Polish newspaper Gazeta Wyborcza, Russian Prime Minister Vladimir Putin condemned the Molotov–Ribbentrop Pact as "immoral."