• Germany, under Nazi dictator Adolf Hitler, and the Soviet Union, under Communist dictator Joseph Stalin, sign the Nonaggression Pact, which secretly accepts Germany’s plan to invade Poland.

  • Germany invades Poland in a blitzkrieg (lightning war). England and France react by declaring war on Germany. This begins the European War, which will become World War II.

  • The Soviet Union invades Finland, occupies part of Poland, and, by threatening invasion, takes over Lithuania, Estonia, and Latvia.

  • Soviet-Finland war ends in Finland’s surrender.

  • Germany invades Norway and Denmark and will soon conquer both countries.

  • Germany invades the Netherlands, Belgium, and Luxembourg.

  • Germany conquers France.

    German troops occupy northern and western France. Pro-German French officials set up a capital in Vichy and run the rest of France under Germany’s watchful eye. Italy, under fascist dictator Benito Mussolini, declares war on England and France.
  • Japanese troops begin to occupy the French colony of Indochina. .

    Japanese troops begin to occupy the French colony of Indochina.
    The United States responds by cutting off oil exports to Japan.
  • September Hundreds of German warplanes begin bombing London every night for 57 nights in attacks that will continue until May 1941. More than 40,000 people will die in the Blitz as Londoners call the air raid campaign.

  • Italy invades Greece. German troops later come to the aid of Italian troops.

  • Japanese Adm. Isoroku Yamamoto begins planning an air attack on Pearl Harbor.

  • “short of war.”

    The United States begins “Lend-Lease,” allowing President Roosevelt to send ammunition and other war supplies to England. No longer a neutral nation, the United States now will give England all help “short of war.”
  • Germany conquers Greece and Yugoslavia.

  • More than three million German troops invade the Soviet Union.

  • “get ready for war”

    Japanese Army and Navy officers say Japan should “get ready for war” against the United States. Gen. Hideki Tojo becomes prime minister in a military-controlled government.
  • The United States tells Japan to get out of China and Indochina. Tojo decides that Japan’s only choice is to go to war.

  • Japan sends diplomats to Washington to try to find ways to avoid war with the United States.

  • Six Japanese aircraft carriers and other warships secretly leave northern Japan and head for Pearl Harbor.

  • The United States cuts off all oil exports to Japan.

  • Japan attacks Pearl Harbor.

    Japan attacks Pearl Harbor. Almost at the same time, Japanese warplanes attack the Philippines and two U.S. islands: Wake and Guam, which are later occupied. Japanese troops invade Malaya and Thailand and seize Shanghai. Later in December Japanese troops invade Burma and Hong Kong.
  • Three days after Pearl Harbor, Germany and Italy declare war on the United States.

  • Manila, Philippines, falls to Japanese troops.

  • Japanese carrier planes bomb Darwin, Australia.

  • First U.S. troops arrive in Australia.

  • Sixteen U.S. bombers, led by Lt. Col. James Doolittle, take off from an aircraft carrier 800 miles (1300 kilometers) off Tokyo and make the first bombing raid against Japan.

  • The U.S. government forces thousands of Japanese-Americans to move from the U.S. West Coast to “relocation” camps in isolated areas.

  • In the battle of the Coral Sea, U.S. warships turn back a Japanese invasion force heading for New Guinea.

  • An aircraft launched from a Japanese submarine drops fire bombs on forests near Brookings, Oregon, in the first bombing of the continental United States.

  • After months of desert fighting, the British Eighth Army in North Africa puts Germany’s Afrika Corps to flight.

  • Atomic bombs are dropped on Hiroshima (August 6) and Nagasaki (August 9).