The politics and diplomacy of World War II begin with the frantic responses of governments to the attack on Poland. The United Kingdom, along with Australia and New Zealand, declare war at 11:15 am. France joins the war at 5:00 pm. A number of nations have declared their neutrality by this point or will do so in the coming weeks while South Africa and Canada will join the Allies at war in the next few days. See timeline of politics and diplomacy during World War II for a detailed chronology of these events.
The Second Battle of the Atlantic begins as the German Navy goes into action to begin denial of the United Kingdom's shipping lanes almost immediately after the United Kingdom's declaration of war with Germany. This campaign would last for the duration of the war, and pit Germany's submarine force, surface raiders, and maritime aircraft against the Allies' merchant shipping convoys and their escorts. See timeline of the Second Battle of the Atlantic for a detailed chronology of this campaign.
September 4, 1939
Allied air operations in Europe begin with raids by the Royal Air Force targets on German naval targets. Early raids are small, but build through the war to become a steady campaign of strategic bombardment against targets throughout Axis-occupied territory in Europe that would only end with the defeat of the Axis in Europe. See timeline of Allied air operations in Europe for a detailed chronology of this campaign.
September 7, 1939
French patrols enter Germany near Saarbrücken. These continue through September 17, 1939 in anticipation of a larger advance. This larger advance is cancelled in part due to the collapase of Poland, leading a lack of operational activity during the period from then to the Battle of France named the Phony War. Meanwhile, the British Expeditionary Force begins arriving in France and takes up positions along the Belgian frontier. See the timeline of the Battle of France for a detailed chronology of the events of the Phony War and the lead up to the Battle of France.
September 17, 1939
The Soviet Union invades Poland from the east, occupying the territory east of the Curzon line as well as Bialystok and Eastern Galicia.
September 25, 1939
German home front measures begin with the start of food rationing. Adolf Hitler is not as earnest as many other nations in bringing war-time measures to the citizens of Germany, as he fears it may erode their support for the war effort. See timeline of the German home front during World War II for a detailed chronology of events.
October
5: The Soviet Union begins talks with Finland to adjust the border between the two countries.
6: Polish resistance in the Polish September Campaign comes to an end. Finland begins mobilizing its army; Hitler speaks before the Reichstag, declaring a desire for a conference with Britain and France to restore peace.
9: Hitler issues orders for preparation of invasion of Belgium, France, Luxembourg and the Netherlands.
10: The German navy suggests occupying Norway to Hitler.
19: Portions of Poland are formally inducted into Germany; the first Jewish ghetto is established at Lublin.
November
4: The Neutrality Acts are enacted in the United States, the "cash and carry" provisions for selling military supplies favour Britain and France.
8: An attempt to assassinate Hitler by a bomb while he makes a speech fails; in the Venlo Incident, two British intelligence agents are captured; Germans appoint Hans Frank Governor General of Poland and begin accelerating anti-Jewish programs there.
17: The Czechoslovak National Committee is organized in Paris.
30: The Soviet Union attacks Finland starting the Winter War.
1: Conscription extended in Britain: all men between 20 and 27 now liable.
4: Hermann Göring placed in charge of German war industries.
5: British cabinet is revised, Oliver Stanley takes over War Office, Lord Reith becomes Minister of Information, and Sir Andrew Duncan takes over Board of Trade.
7: General Semyon Timoshenko placed in command of Soviet troops against Finland.
8: Bacon, butter, and sugar rationing begins in Britain.
10: The Mechelon Incident : two German officers crashland in Mechelon, Belgium carrying copies of the planned invasion of France. This incident leads to a postponement and revision of the invasion.
11: Meat rationing begins in France.
14: Japanese Prime Minister Abe Nobuyuki and his cabinet resign and Admiral Mitsumasa Yonai is named as Prime Minister.
February
1: Japanese Diet announces record high budget with over half its expenditures being military.
5: Britain and France decide to intervene in Norway to cut off the iron ore trade — in anticipation of an expected German occupation and ostensibly to open a route to assist Finland. The operation is scheduled to start about March 20.
9: Erich von Manstein is placed in command on German XXXIII Armor Corps, removing him from planning the French invasion.
14: British government calls for volunteers to fight in Finland.
15: Soviet army captures Summa in Finland thereby breaking through the Mannerheim Line.
16: British destroyer HMS Cossack forcibly removes 299 British POWs from the German transport Altmark in neutral Norwegian territorial waters.
17: Manstein presents his plans for invading France via the Ardennes forest to Hitler.
21: General Nickolaus von Falkenhorst is placed in command of the upcoming German invasion of Norway; work begins on the construction of Auschwitz.
24: The Ardennes plan for invading the west is adopted.
March
3: Soviets begin attacks on Viipuri, Finland's second largest city.
5: Finland tells the Soviets they will agree to their terms for ending the war.
12: Finland signs a peace treaty with the Soviet Union.
16: German air raid on Scapa Flow causes first British civilian casualties.
18: Mussolini agrees with Hitler that Italy will enter the war 'at an opportune moment".
21: Paul Reynaud becomes Prime Minister of France following Daladier's resignation the previous day.
28: Britain and France make a formal agreement that neither country will seek a separate peace with Germany.
1: Hitler gives the go ahead for the invasion of Norway and Denmark.
3: Churchill is appointed chairman of the Ministerial Defense Committee following the resignation of Lord Chatfield.
5: Chamberlain makes an ill-timed remark that Hitler has "missed the bus".
9: Denmark and Norway invaded by Germany; Denmark surrenders.
10: First Battle of Narvik, British destroyers and aircraft successfully make a surprise attack against a larger German naval force. A second attack on April 13 will also be a British success.
14: British and French troops begin landing in Norway.
30: British and French troops begin evacuating from Norway.
May
5: Norwegian government in exile established in London.
14: Paris occupied by German troops; French government moves again, this time to Bordeaux.
16: Philippe Pétain becomes premier of France upon the resignation of Reynaud's government.
17: Sinking of liner HMT Lancastria off St Nazaire while being used as a British troopship - Britain's worst maritime disaster.
18: General De Gaulle forms the Comité Français de la Libération Nationale , a French government in exile; Estonia, Latvia and Lithuania are occupied by the Soviet Union.
21: Franco-German armistice negotiations begin at Compiegne.
22: Franco-German armistice signed.
24: France officially surrenders to Germany; Franco-Italian armistice signed.
28: General De Gaulle recognised by British as leader of Free French.
7: Germany invades Romania to restrain the Romanian Army.
12: Any German invasion of Britain postponed until Spring 1941 at the earliest.
28: Italy issues ultimatum to Greece - Prime Minister Metaxas replies "So it is war" (celebrated as "Okhi!" ("No!") Day in Greece); Italian forces invade Greece.
November
11: British naval forces launch attack against Italian navy at Taranto. Swordfish bombers from HMS Illustrious damage three battleships, two cruisers and multiple auxillary craft.
4: British commandos carry out attack on oil facilities at Narvik in Norway.
11: President Franklin Delano Roosevelt signs the Lend Lease Act allowing Britain, China and other allied nations to purchase military equipment and to defer payment until after the war.
27: Crown Prince Peter becomes Peter II of Yugoslavia and takes control of Yugoslavia after an army coup overthrows the pro-German government of the Prince Regent.
30: The Afrika Korps begins the German offensive in North Africa.
April
6: German, Hungarian and Italian forces invade Yugoslavia and Greece. Italian Army in Ethiopia surrenders.
12: Britain and Soviet Union sign mutual defence agreement, promising not to sign any form of separate peace agreement with Germany.
25: Iran occupied by Britain and the Soviet Union.
August
6: American and British governments warn Japan not to invade Thailand.
25: British and Soviet troops invade Persia (Iran), to save the oilfields of Abadan and the important railways and ways to Russia for the supply of war material.
21: Japanese establish beachhead on the north coast of New Guinea, in the Buna-Gona area; small Australian force begins rearguard action on the Kokoda Track.
27: First Battle of El Alamein ends.
August
7: Operation Watchtower begins the Battle of Guadalcanal as American forces invade Gavutu , Guadalcanal, Tulagi and Tanambogo in the Solomon Islands.
13: General Bernard Montgomery appointed commander of British Eighth Army in North Africa.
19: Operation Jubilee, a raid by British and Canadian forces on Dieppe in France, ends in disaster.
9: German and Italian forces in Tunisia announce surrender to British.
24: Admiral Karl Dönitz orders the majority of U-Boats to withdraw from the Atlantic.
July
4: General Wladyslaw Sikorski and several other members of the Polish government in exile are killed in what is ostensibly an air accident in Gibraltar - some suspect that the 'accident' was actually caused on Stalin's orders.
