Question: The Molotov–Ribbentrop Pact was signed by the Foreign Minister of Germany who held the post during what years?

Context paragraphs:
Pact Ribbentrop - Beck: Pact Ribbentrop - Beck (Polish: Pakt Ribbentrop - Beck) is an alternative history novel by Polish writer and historian Piotr Zychowicz.  The book, whose full title is "Pact Ribbentrop - Beck, or How Poles could have defeated the Soviet Union alongside the Third Reich" (Polish: "Pakt Ribbentrop - Beck czyli jak Polacy mogli u boku III Rzeszy pokonać Związek Radziecki"), was published in 2012 by Dom Wydawniczy Rebis from Poznań.  The author argues that the government of the Second Polish Republic should have accepted Adolf Hitler's offer of a joint Polish - German attack on the Soviet Union, together capturing Moscow.  "Beck" refers to Józef Beck, Poland's foreign minister in the 1930s.

Military occupations by the Soviet Union: During World War II, the Soviet Union occupied and annexed several countries effectively handed over by Nazi Germany in the secret protocol Molotov–Ribbentrop Pact of 1939.  These included Eastern Poland (incorporated into two different SSRs), as well as Latvia (became Latvian SSR), Estonia (became Estonian SSR), Lithuania (became Lithuanian SSR), part of eastern Finland (became Karelo-Finnish SSR) and eastern Romania (became the Moldavian SSR and part of Ukrainian SSR).  Apart from Molotov–Ribbentrop Pact and post-war division of Germany, USSR also occupied and annexed Carpathian Ruthenia from Czechoslovakia in 1945 (became part of Ukrainian SSR).

German–Soviet Axis talks: In October and November 1940, German–Soviet Axis talks occurred concerning the Soviet Union's potential entry as a fourth Axis Power in World War II.  The negotiations, which occurred during the era of the Molotov–Ribbentrop Pact, included a two-day Berlin conference between Soviet Foreign Minister Vyacheslav Molotov, Adolf Hitler and German Foreign Minister Joachim von Ribbentrop, followed by both countries trading written proposed agreements.  After two days of negotiations from 12 to 14 November 1940, Germany presented the Soviets with a draft written Axis pact agreement defining the world spheres of influence of the four proposed Axis powers (Japan, Germany, Soviet Union, Italy).  Hitler, Ribbentrop and Molotov tried to set German and Soviet spheres of influence; Hitler encouraged Molotov to look south to Iran and eventually India while preserving German access to Finland's resources, and to remove Soviet influence in the Balkans.  Molotov remained firm, seeking to remove German troops from Finland and gain a warm water port in the Balkans.  Soviet foreign policy calculations were predicated by the idea that the war would be a long - term struggle and therefore German claims that Britain would be defeated swiftly were treated with scepticism.  In addition Stalin sought to remain influential in Bulgaria and Yugoslavia.  These factors resulted in Molotov taking a firm line.  According to a Columbia University academical source, on 25 November 1940, the Soviets presented a Stalin-drafted written counterproposal where they would accept the four power pact, but it included Soviet rights to Bulgaria and a world sphere of influence centered on the area around modern Iraq and Iran.  Germany did not respond, leaving the negotiations unresolved.  Regarding the counterproposal, Hitler remarked to his top military chiefs that Stalin "demands more and more", "he's a cold-blooded blackmailer" and that "a German victory has become unbearable for Russia" so that "she must be brought to her knees as soon as possible."  Germany broke the Molotov-Ribbentrop Pact in June 1941 by invading the Soviet Union.

Joachim von Ribbentrop: Ulrich Friedrich Wilhelm Joachim von Ribbentrop (30 April 1893 – 16 October 1946), more commonly known as Joachim von Ribbentrop, was Foreign Minister of Nazi Germany from 1938 until 1945.

Molotov–Ribbentrop Pact: The Molotov–Ribbentrop Pact, also known as the Nazi–Soviet Pact, the German–Soviet Non-aggression Pact or the Nazi German-Soviet Pact of Aggression (officially: "Treaty of Non-aggression between Germany and the Union of Soviet Socialist Republics"), was a neutrality pact between Nazi Germany and the Soviet Union signed in Moscow on 23 August 1939 by foreign ministers Joachim von Ribbentrop and Vyacheslav Molotov, respectively.  The pact was followed by the German-Soviet Commercial Agreement in February 1940.

German–Soviet Frontier Treaty: The German-Soviet Frontier Treaty was a second supplementary protocol, of the 1939 Hitler-Stalin Pact (known as the "German-Soviet Treaty of Nonaggression", or by its original name of the "German–Soviet Treaty of Friendship, Cooperation and Demarcation").  It was a secret clause as amended on September 28, 1939 by Nazi Germany and the Soviet Union after their joint invasion and occupation of sovereign Poland.  It was signed by Joachim von Ribbentrop and Vyacheslav Molotov, the foreign ministers of Germany and the Soviet Union respectively, in the presence of Joseph Stalin.  The treaty was a follow-up to the first secret protocol of the Molotov–Ribbentrop Pact signed on August 23, 1939 between the two countries prior to their invasion of Poland and the start of World War II in Europe.  Only a small portion of the protocol which superseded the first treaty was publicly announced while the spheres of influence of Nazi Germany and the Soviet Union remained classified.  The third secret protocol of the Pact was signed on January 10, 1941 by Friedrich Werner von Schulenberg, and Molotov, whereas Germany renounced its claims to portions of Lithuania, only a few months before their anti-Soviet Operation Barbarossa.

Karl Selter: Karl Selter (born June 24, 1898 in Koeru, Estonia – died January 31, 1958 in Geneva, Switzerland) was an Estonian politician and a Minister of Foreign Affairs of Estonia.  He served as Minister of Economic Affairs from 1933 to 1938 and as minister of Foreign affairs from 1938 to 1939.  His historically most memorable act was to sign a non-aggression and mutual assistance treaty with the Soviet leaders in Moscow in September 1939.  This was also his personal and national Estonian most tragic act.  It followed a brutal ultimatum from the Soviet Foreign Minister, Vyacheslav Molotov on September 24.  Molotov said to Setler: Estonia gained sovereignty when the Soviet Union was powerless, but you “don’t think that this can last… forever… The Soviet Union is now a great power whose interests need to be taken into consideration.  I tell you—the Soviet Union needs enlargement of her security guarantee system; for this purpose she needs an exit to the Baltic Sea … I ask you, do not compel us to use force against Estonia.”  The enforced in this manner treaty gave the Soviet army a right to set up military bases in Estonia, and it significantly reduced Estonia's independence until Estonia was formally incorporated into the Soviet Union between June and August 1940.  Selter left Estonia in November 1939, resigning both as Foreign Minister and as a member of Parliament.  He moved to Geneva, Switzerland as a diplomat.  After Germany occupied Estonia between 1941 and 1944, and after it was re-incorporated into the Soviet Union in 1944, he stayed in Switzerland as an exiled diplomat and politician.

Molotov–Ribbentrop Pact negotiations: The Molotov–Ribbentrop Pact was an August 23, 1939, agreement between the Soviet Union and Nazi Germany colloquially named after Soviet foreign minister Vyacheslav Molotov and German foreign minister Joachim von Ribbentrop.  The treaty renounced warfare between the two countries.  In addition to stipulations of non-aggression, the treaty included a secret protocol dividing several eastern European countries between the parties.

Timeline of the Molotov–Ribbentrop Pact: The timeline of the Molotov–Ribbentrop Pact is a chronology of events, including Molotov–Ribbentrop Pact negotiations, leading up to, culminating in, and resulting from the Molotov–Ribbentrop Pact.  The Treaty of Non-aggression between Nazi Germany and the Soviet Union was signed in the early hours of August 24, 1939, but was dated August 23.

Baltic Appeal: The Baltic Appeal (Estonian: "Balti apell" , Latvian: "45 baltiešu memorands" , Lithuanian: "45 memorandumas" ) was a public letter to the general secretary of the United Nations, Soviet Union, East and West Germany, and signatories of the Atlantic Charter by 45 Estonian, Latvian and Lithuanian citizens.  Sent on 23 August 1979, the 40th anniversary of the Molotov–Ribbentrop pact, the appeal demanded public disclosure of the pact and its secret protocols, annulment of the pact "ab initio", and restoration of the independence of the Baltic states, then occupied by the Soviet Union.

Supporting paragraphs: Molotov–Ribbentrop Pact Joachim von Ribbentrop
Answer: 1938 until 1945