In some sense wars start years even decades before the shooting begins. Once a war breaks out one might say it was inevitable. In many respects the roots of World War Two have their early beginnings in World War One (or further back if one wishes to trace back ad nauseum).
There is no “official” date for the start of World War Two. Two dates may reasonably be accepted as the start or rather starts; July 7, 1937 in Asia and September 1, 1939 in Europe. Then in December 1941 the two hemisphere wars merged into a full blown world war. Let’s examine what occurred on those dates.
WAR BEGINS IN ASIA
Japan’s economy was hit hard by the world depression that began in 1929. With no solutions forthcoming from Japan’s politicians the country turned to its military leaders who embarked on imperial expansion. The main benefit of imperialism is of course economic. It gives the ruling nation new sources of raw materials, labor, industries, and markets in addition to what was called “buffer” zones from enemies.
In September 1931 the Japanese army invaded Manchuria, the far northeast Chinese province that borders on Russia, Mongolia, Korea, and the Yellow Sea By February 1932 Chinese resistance had all put faded and Japan set up a puppet state in what it called Manchuko. Chinese guerillas continued to harass the Japanese throughout their occupation of Manchuria. By 1937 Japan also controlled most of Beijing.
On the night of July 17, 1937 Japanese troops in Beijing were conducting firing drills near the Lugou Bridge (Marco Polo Bridge) in the southwest section of the city. Chinese troops on the other side of the bridge believed they had come under fire and responded in kind. As often occurs, the incident escalated and turned into a full scale war between China and Japan. In December 1937 the Japanese captured Nanjing (Nanking) and during a six-week period (Rape of Nanking) Japanese troops massacred nearly 300,000 Chinese soldiers and civilians and raped an estimated 50,000 Chinese women.
World War Two in Asia had begun.
WAR BEGINS IN EUROPE
In 1933 Adolf Hitler came to power in Germany as Chancellor of the Weimar Republic. Through a series of strong-arm and manipulative tactics he soon transformed it into Nazi Germany, a single dictatorship. Germany too had been hit hard by depression and the people were ready for a strong leader. While German industry was revived through public construction and military rearmament, Hitler embarked on his expansionist policy of Lebensraum (living space).
In 1936 Hitler ordered the military to be prepared for all-out war in four years time. Germany reoccupied the Rhineland; a move that violated the Versailles treaty (which had ended World War I). That same year Hitler signed an “Axis” agreement with Benito Mussolini, Italy’s fascist dictator. He also signed a “non-aggression” pact with Russia’s Joseph Stalin.
In 1938 after threat of force, Austria united with Germany and later in the year western Allies England and France agreed to cede the Sudetenland (western Czechoslovakia) to Germany in what was called the Munich Agreement. At first the western Allies believed they had staved off war but then in early 1939 Hitler violated the agreement and invaded the other half of Czechoslovakia. England and France prepared for war.
On September 1, 1939 Hitler’s forces invaded western Poland in a blitzkrieg (lightning) attack. Two days later, honoring a previous treaty with Poland, England and France declared war on Germany.
World War II in Europe had begun.
AMERICA AND RUSSIA PULLED INTO WAR
While China fought to hold off Japan, France fell to Germany on June 22, 1940. Hitler turned his attention to defeating England and the Battle of Britain began. By the beginning of 1941 England had staved off German invasion but Hitler was still master of mainland Europe. Then in 1941 Hitler ignored his anti-aggression pact with Russia and sent three million German soldiers in an attack on Russia. By December 1941 German forces were at the outskirts of Moscow but harsh winter weather and the tenacity of the Russians held them back. For the next three years Russia and Germany engaged in fierce fighting.
Following the Japanese invasion of Indochina (Cambodia, Vietnam, Laos) in 1940 the United States stopped sales of war materiel to Japan. When France fell to Germany in June 1940, Japan easily occupied Indochina. In consequence, the United States enacted an oil embargo aimed to prevent further Japanese expansion as well as feed its own growing need for oil. With its main supply of oil cutoff and needing it to fuel its military and industry, Japan set about planning the takeover of the oil-rich Dutch East Indies while at the same time planning a surprise attack on US naval forces at Pearl Harbor and the Philippines. Japan reasoned that war with the US was inevitable and in order to gain a quick victory and peace it needed to strike a first decisive blow.
After further negotiations broke down, Japanese military leaders were given the go-ahead for the attacks. On the morning of December 7, 1941 fighter and bomber aircraft from nearby Japanese aircraft carriers attacked Pearl Harbor in two separate waves. Although the attack was a tactical victory for Japan, its main objective failed. Admiral Yamamoto, the man who planned the attack, summed it up when he said “”I’m afraid all we have done is awaken a sleeping giant and fill him with a terrible resolve.”
Outraged by the attack and the loss of 2402 American lives at Pearl Harbor the United States declared war on Japan on December 8, 1941. Hitler then declared war on the United States and the United States reciprocated with a declaration of war on Germany on December 11, 1941.
World War Two had “officially” begun.
Paul Johnson: A History of the American People
Iris Chang: The rape of Nanking: the forgotten holocaust of World War II
Winston Churchill: The Second World War
AJP Taylor: The Origins of the Second World War