World War II

World War II was a huge war that involved most of the world's countries from 1939 to 1945. It was fought between two groups. The Allies included the United States, Britain, the Soviet Union, France, and China. The Axis powers were Germany, Italy, and Japan. By the time the war ended, between 70 and 85 million people had died. It was the deadliest war in human history.

Causes

The war had many causes, but most started with the end of World War I in 1918. Germany lost that war and was forced to sign a harsh peace treaty. The treaty made Germany pay huge sums of money and give up land. In the 1920s and 1930s, Germany's economy collapsed. Millions of people lost their jobs.

In this hard time, a man named Adolf Hitler rose to power. He led a political party called the Nazis. Hitler promised to make Germany strong again. He also blamed Germany's problems on Jewish people and other groups, spreading hatred and lies. He became Germany's leader in 1933 and quickly built up the army.

Meanwhile, Japan was expanding its empire in Asia. It had already invaded parts of China in the 1930s. Italy, led by a dictator named Benito Mussolini, also wanted more land. The three countries became allies.

The war begins

The war started on September 1, 1939, when Germany invaded Poland. Two days later, Britain and France declared war on Germany. Within a year, Germany had taken over much of Europe, including France. Only Britain still stood against the Nazis in the west.

Germany then bombed British cities night after night in what was called the Blitz. British pilots fought back in the skies above their homeland. This battle, known as the Battle of Britain, was the first major battle fought entirely in the air.

In June 1941, Hitler made one of his biggest mistakes. He invaded the Soviet Union, breaking a deal he had made with its leader, Joseph Stalin. The Soviet Union joined the Allies. The fighting on the eastern front was the largest land war ever. Millions died on both sides.

America joins

The United States stayed out of the war at first. That changed on December 7, 1941. Japan attacked the American naval base at Pearl Harbor in Hawaii without warning. More than 2,400 Americans were killed. The next day, the United States declared war on Japan. Germany and Italy then declared war on the United States.

Now the war was truly global. Battles raged across Europe, North Africa, and the Pacific Ocean. American factories began producing tanks, ships, and planes at an amazing speed. Women took jobs in factories while millions of men served in the military.

The Holocaust

While the war went on, Nazi Germany was carrying out one of the worst crimes in history. Hitler's government built camps where they imprisoned and murdered Jewish people from across Europe. About six million Jews were killed, along with millions of Roma people, disabled people, Soviet prisoners, and others the Nazis hated. This mass murder is called the Holocaust. The world did not fully understand what was happening until Allied soldiers freed the camps near the end of the war.

Turning the tide

By 1942, the Allies began to win major battles. The Soviets stopped the German army at the city of Stalingrad after months of brutal fighting. American forces slowed Japan's advance at the Battle of Midway in the Pacific.

On June 6, 1944, Allied troops landed on the beaches of Normandy in France. This day is called D-Day. About 156,000 soldiers crossed the English Channel in the largest sea invasion ever. They began pushing the Germans back across Europe.

The end

By spring 1945, Allied armies were closing in on Germany from both east and west. Hitler killed himself in his underground bunker in Berlin. Germany surrendered on May 8, 1945. People celebrated in the streets of cities around the world.

Japan kept fighting. To end the war quickly, the United States dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945. These were the most powerful weapons ever used in war. Each bomb destroyed an entire city in seconds. More than 100,000 people were killed, most of them civilians. Japan surrendered a few days later.

Historians still debate whether using the atomic bombs was the right choice. Some argue the bombs ended the war faster and saved lives that would have been lost in a long invasion. Others say Japan was already close to surrender and the deaths were not needed.

The war reshaped the world. The United States and the Soviet Union became the two strongest countries on Earth. Their rivalry would soon lead to a new struggle called the Cold War.