In July 1937, Japan launched a full-scale invasion of China, starting the second Sino-Japanese War.
German Invasion of Poland
On September 1st, 1939, Nazi Germany invaded Poland, beginning the second world war.
Battle of Britain (First Bombing of London)
During the summer and fall of 1940, the German and British air forces fought over the United Kingdom. September 7th, 1940, was the first bombing of London, England.
Signing of the Tripartite Pact
The Tripartite Pact was signed on September 27th, 1940, in Berlin, Germany, by Germany, Japan, and Italy, forming the Axis powers.
Ratification of the Lend-Lease Act
On March 11th, 1941, the Lend-Lease Act was ratified, allowing the U.S. military to aid other foreign countries.
German Blitzkrieg on Soviet Union
June 22nd, 1941, marked the start of Operation Barbarossa, the code name for Germany's invasion of the Soviet Union. The Soviets suffered initial defeats due to the Germans' usage of blitzkrieg tactics.
Siege of Leningrad
On September 8th, 1941, Axis forces began the siege of Leningrad. The siege was lifted on January 27th, 1944, more than two years after its inception, after a failure of the Axis to "starve" the city of resources.
Japanese Bombing of Pearl Harbor
Japanese planes attacked the United States Naval Base in Pearl Harbor, Hawai'i. Casualties reached more than 2,300.
Formation of the United Nations
On January 1st, 1942, 26 nations signed the Declaration of the United Nations, stating that they would use their full resources against the Axis.
On January 20th, 1942, Nazi officials gathered in Berlin, Germany, to discuss the Jewish Question.
The Battle of Midway
On June 4th, 1942, the Battle of Midway began, marking the turning point in the Pacific theatre and the slow decline of Japanese dominance.
On June 6th, 1944, the Allies invaded the coast of Northern France in an effort to establish a western front of the war.
On February 4th, 1945, the Yalta Conference convened in the Crimea. The United States, Great Britain, and the Soviet Union discussed important decisions regarding the future of the war and the postwar world.
American Capture of Iwo Jima
On March 26th, 1945, the island of Iwo Jima was declared secured, providing an advantageous position for United States military in the war against Japan.
Suicide of Adolf Hitler
On April 30th, 1945, Adolf Hitler committed suicide by gunshot.
On May 8th, 1945, Germany surrendered to the Allies. This day is celebrated as VE Day or "Victory in Europe Day."
American Capture of Okinawa
On June 21st, 1945, the island of Okinawa was declared secured, providing an advantageous position for United States military in the war against Japan.
On July 17th, 1945, a conference convened between the Allies (Soviet Union, United States, Great Britain) in Potsdam, Germany, to discuss post-war issues.
"Little Boy" Dropped on Hiroshima
The United States dropped an atomic bomb on Hiroshima, Japan, on August 6th, 1945, the first ever usage of atomic weapons in warfare. Even after the destruction of Hiroshima, the Japanese refused to surrender.
"Fat Man" Dropped on Nagasaki
The United States dropped an atomic bomb on August 6th, 1945, on Nagasaki, Japan. Japan surrendered soon afterwards.
On August 14th, 1945, Japan surrendered unconditionally to the Allies. This day is celebrated as VJ Day or "Victory over Japan Day."
Promulgation of the Truman Doctrine
On March 12, 1947, the Truman Doctrine was set forth, stating that the U.S. would support Greece and Turkey with economic and military aid to prevent their conversion to Soviet control.
Ratification of the Marshall Plan
On April 3rd, 1948, President Truman signed the Economic Recovery Act, which proposed that the United States provide economic assistance to postwar Europe. It later became known as the Marshall Plan, after the Secretary of State George Marshall, who first proposed it.
Creation of NATO
On April 4th, 1949, 12 countries signed the North Atlantic Treaty, creating NATO (The North Atlantic Treaty Organization), an intergovernmental military alliance in which members pledge to mutual defense of one another.
Formation of the People's Republic of China
The People's Republic of China was formed in 1949 after Mao Zedong and the Chinese Communist Party defeated Jiang Jieshi and the Nationalist Party.
On June 25th, 1950, the Korean War began between South Korea (supported by the United Nations) and North Korea (supported by China and the Soviet Union), dividing the peninsula along the 38th parallel.
Death of Stalin; Khrushchev's Rise to Power
On March 5th, 1953, Joseph Stalin died, causing a power struggle from which, after years of dispute, Khrushchev emerged.
Warsaw Pact Conference
On May 11th, 1955, the Warsaw Pact Conference convened in Warsaw, Poland, to establish a military agreement between the Soviet Union and seven of its satellite nations.
In December, 1956, the Vietnam War began between the Capitalist forces of South Vietnam, supported by the United States, and North Vietnam, supported by China and the Soviet Union. It was one of the many proxy wars started due to capitalist-communist tension.
Launch of Sputnik
On October 4th, 1957, Sputnik, the world's first artificial satellite, was launched into space by the Soviets as a product of competition from the Cold War.
Bay of Pigs Revolution
On April 17th, 1961, Cuban exiles launched an invasion in an attempt to overthrow the communist regime headed by Fidel Castro.
Construction of the Berlin Wall
On August 13th, 1961, the construction of the Berlin Wall, a barrier separating West Berlin from East Berlin, illustrating the competition of the capitalist economies supporting West Berlin, and the communist economies supporting East Berlin.
Cuban Missile Crisis
On October 14th, 1962, the two superpowers came closest to nuclear war when Soviet missile silos were built in Cuba. The tension was later defused, and the missiles were removed by order of Khrushchev.
Resignation of Gorbachev
Gorbachev, the President of the Soviet Union who renewed attacks on Stalinism and instigated policies of glasnost (openness) and perestroika (restructuring), resigned one day before the dissolution of the Soviet Union.
Fall of Soviet Union
On December 26th, 1991, the dissolution of the Soviet Union was formalized, following the resignation of Soviet President Mikhail Gorbachev, marking the end of the Cold War.