February 20, 1938: Hitler in a speech states:
“In our relationswith the state with which we had had perhaps the greatest differences not only has there been a détente, but in the course of years there has been a constant improvement in relations. The Polish state respects the national conditions in this state and both the city of Dantzig and Germany respect Polish rights. And so the way to an understanding has been successfully paved, an understanding which, beginning with Dantzig, has today in spite of the attempts of many mischief-makers finally succeeded in taking the poison out of the relations of Germany and Poland and transforming them into a sincere and friendly cooperation.”
Green Books: Trials of war criminals before the Nuremberg Military Tribunal under Control Council, no 10, vols 12-14 (London H.M.S.O. 1947-1949) p. 326.

September 26, 1938: further to his speech of March 7, 1936 describing “the détente and constant improvement in relations”, and less than a year before attacking Poland, Hitler declares:
“In Poland there rules not a democracy, but a man, and with him I succeeded in precisely 12 months in coming to an agreement which for 10 years, to begin with, entirely removed the danger of conflict. We are all convinced that this agreement will bring lasting pacification”.
Green Books: Trials of war criminals before the Nuremberg Military Tribunal under Control Council, no 10, vols 12-14 (London H.M.S.O. 1947-1949) p. 326.

October 1, 1938: German troops occupy the Czechoslovakian Sudetenland. Almost all of the 20,000 Jews in the Sudetenland soon flee to the still independent provinces of Bohemia and Moravia.
October 2 1938: Polish troops occupy Teschen in Czechoslovakia.

October 21, 1938: less than a month after his declaration announcing that his agreement with Poland “for 10 years, to begin with, entirely removed the danger of conflict”, Hitler orders Keitel to make preparations to enable German troups to occupy the Free city of Danzig by surprise.
Green Books: Trials of war criminals before the Nuremberg Military Tribunal under Control Council, no 10, vols 12-14 (London H.M.S.O. 1947-1949) p. 326.

October 24, 1938: German Foreign Minister Ribbentrop and Polish Ambassador Lipski meet at Berchtesgaden. Ribbentrop invites Polish Foreign Minister Beck to visit Berlin and puts forward the following suggestions: (1) Danzig to be a German city. (2) Free port for Poland in Danzig with communications assured by extraterritorial railroad and highway through Danzig. (3) An Extraterritorial zone one kilometer wide for a railroad and highway across the Polish Corridor uniting the two portions of Germany carved out at Versailles. (4) Both nations to recognize and guarantee their frontiers. (5) An extension of the German-Polish treaty of Friendship. These proposals are standing and open until August 10, 1939, when Poland will reject them and declare "any intervention by the Reich Government (will be regarded as) an act of aggression."

October 27, 1938: Hitler orders the reexpulsion from Germany to Poland of Jews, who had migrated there from Poland. A part of the foreign press claims that some German Jewish persons of Polish origin are added to the emigrants. Some 15,000 "stateless" Jews are forced to leave their homes throughout Germany and to go, with only one suitcase, to the nearest railway station. They are then taken through the night to the German-Polish border and forced across at gun point.
Himmler orders the police to collect all Polish Jews in Germany with valid passports and deport them before October 29th.

November 24, 1938: less than two month after Hitler’s declaration announcing that his agreement with Poland “for 10 years, to begin with, entirely removed the danger of conflict”, Keitel issues orders based on Hitler’s instructions of 21 October that preparations be made to enable German troups to occupy the Free city of Danzig by surprise.
Green Books: Trials of war criminals before the Nuremberg Military Tribunal under Control Council, no 10, vols 12-14 (London H.M.S.O. 1947-1949) p. 326.

January 24, 1939: Goering orders Reinhard Heidrich to establish the Reich Central Office for Jewish Emigration to organize and accelerate the emigration of the Jews. Heydrich names Gestapo chief Heinrich Mueller to head the department. Almost 80,000 Jews will leave Germany in 1939.
Klee, Dressen & Riess: The Good Old Days.
Germany and Poland reach an agreement on Jewish deportees. One thousand Jews at a time may return to Germany to settle their accounts. A special proprietary account for this purpose will be set up in Germany for deposits only.
Hershel and Abraham Edelheit. A World in Turmoil: An Integrated Chronology of the Holocaust and World War II (Bibliographies and Indexes in World History). Greenwood Press - 1991.

January 25 1939: Meeting in Chateau Vignolle in Paris suburb between the British (Mathematicians Alfred Knox and Alan Turing) who had learned details about the Enigma machine from Richard Lwinski, a Polish Jew of the Warsaw getto, the French who were monthly receiving the encoding positions of the wheels from a spy in Germany, and the Polish mathematicians who had found a way to decipher the messages sent by the machine. They decide to move every known element on deciphering Enigma messages into Bletchley Park near London where the British had, under Menzies impulse financed Alan Turing machine “Ultra” for deciphering Enigma message. The machine was not really operational as yet but was carrying exceptional hopes.
Cave Brown, Anthony. Bodyguard of lies. p.23

March 23, 1939: The Polish government rejects Germany's proposals for Danzig.

April 3, 1939: The OKW (Oberkommando der Wehrmacht: Armed Forces High Command) submits to Hitler the “Directive for the Unified Preparation of the Wehrmacht for War 1939/1940.” Hitler then issues a war directive marked "Most Secret" and has it delivered by hand to his senior war commanders. “Since the situation on Germany's eastern frontier has become intolerable and all political possibilities have been exhausted,” it began, “I have decided upon a solution by force.” Preparations for the attack on Poland, “Case White” (Operation White), “must be made so that the operation can be carried out any time from September 1, 1939.”
Shirer, William. The rise and fall of the Third Reich. Simon & Schuster, NY – 1960. Fawcet Cress ed. –New York – 1962
Rossino, Alexander B. Hitler strikes Poland Blitzkrieg, ideology, and atrocity. p. 8

May 23, 1939: Hitler orders the Military High Command to prepare for war with Poland. Goebbels propaganda machine begins accusing the Poles of committing atrocities against their German-speaking minority.
Taylor Fred (Ed.) The Goebbels Diaries. Putnam Pub Group - 1983.

Shirer, William. The rise and fall of the Third Reich. Simon & Schuster, NY – 1960. Fawcet Cress ed. –New York – 1962
July 24, 1939: Colonel Eduard Wagner, the quartermaster general of the General Staff, hands down the special regulation for “Case White” : “Police powers belong solely to the institution that possesses executive authority (i. e. to make arrests and execution). Just as the exercise of police power in Germany is the domain of of the established [police] institutions, its exercise in enemy territory is entrusted to the representatives of those institutions. All plice forces are therefore to operate according to the instructions of the institution that possesses executive authority and its responsible representatives”.
Fall Weiss – Sonderbestimmungen zu den Anordnungen fuer die Versorgung, OKH/6 Abt, Gen St. d. Heeren, 24 July 1939 in NARA RG 242 T-78 reel 351

July 31, 1939: Heydrich signs the document -prepared by Werner Best following Heydrich and Wagner’s meeting- called “Guidelines for the Foreign Operations of the sipo and the SD”. “By agreement with Army High Command… the task of the Security Police Einsatzkommandos is combating all elements in foreign territory and behind the fighting troops that are hostile to the Reich and the German people…” Gestapo and sipo officers would be responsible for checking the names of arrested and political and racial opponents against the so-called sonderfahndungslisten or Wanted Persons Lists that each Einsatzgrup carried with it in Poland. Last the officers of the SD were charged with establishing a network of informant in the occupied territory, gathering intelligence on enemy political organization s, and with ensuring the safe transportation of seized material to Berlin for analysis.
Zentralstelle der Landesjustizverwaltungen, Ludwigsburg (Central office of Justice Administration for the German States) VI 415 AR 1310/65 E16, 10 February 1972 p 393

August 9, 1939: Germany issues an official warning to the Polish government in Warsaw, saying that another comminatory note to Danzig will result in strained Polish-German relations, with Poland being responsible.
German Ambassador von Dirksen, preparing to depart on leave to Germany, visits British Foreign Secretary Lord Halifax. Halifax questions von Dirksen over the "sharp tone of the German press concerning Danzig." Dirksen replies that it is the fault of the Polish newspaper Czas which has published a statement that if there were any attempt to incorporate Danzig into the Reich, Polish troops would open fire on the Free City.
Howarth, Stephen. August '39: The Last Four Weeks of Peace. Mercury House - 1989.

August 22, 1939: Chamberlain writes a letter to Hitler, warning him the German-Soviet Agreement will not alter Britain's obligation to come to the aid of Poland. He gives a fighting speech, to be broadcast by the BBC, saying it is unthinkable that Great Britain should not carry out its obligations to Poland. Sir William Seeds, British Ambassador in Moscow, accuses Molotov of negotiating in bad faith.
At the Berghof, Hitler gives his generals a long monologue referring to the Reich’s rapidly deteriorating relations with Poland and concluding with the statement that the destruction of Poland “starts on Saturday morning” (August 26). During the speech he makes clear that the officers should avoid viewing the military campaign in traditional terms. The aim of this war is the wholesale destruction of Poland, “the elimination of living forces, not the arrival at a certain line.” He demands the campaign to be carried out with the “greatest brutality and without mercy.”
Nuerenberg Trial Document PS-1014 “Fuehrer’s speech to the Commanders in Chief” 22 August 1939. Trials of War Criminals before the Nuerenberg Military Tribunals [Blue Books] Vol 10 p 702
Hitler proclaims to the commanders of the armed services: “Our strength is in our quickness and our brutality. Genghis Khan had millions of women and children killed by his own will and with a gay heart. History sees him only as a great state builder... Thus for the time being I have sent to the East only my "Death's Head Units" with the order to kill without pity or mercy all men, women, and children of Polish race or language. Only in such a way will we win the vital space that we need. Who still talks nowadays of the extermination of the Armenians?”)
Breitman, Richard. The architect of Genocide. Alfred A. Knopf, New York - 1991. p 43 & note on p 261: Combs, voice of the SS, 22. D’Alquen SS File, Berlin Document Center.
Winfried Baumgart in his “Zur Ansprache des Fuehrers am 22. August 1939“ Vierteljahrhefte fuer Zeitgeschichte 19, no 2 (July 1971): 303, confirms D’Alquen’s file mentionning a document given to the American journalist Louis Lochner by Hermann Maass in 1939. Maass himself had been asked to forward the document to Lochner by Colonel General Ludwig Beck, a known member of the military opposition to Hitler, who claimed an unnamed officer as his source. The cloudy origin of the document is likely the reason why it was not entered as evidence at the Nuerenberg war crimes proceedings. But D’Alquen’s SS file clears any doubt.