This global conflict split a majority of the world's nations into two opposing military alliances: the Allies and the Axis. Spanning much of the globe, World War II resulted in the deaths of over 70 million people, making it the deadliest conflict in human history.[1]
World War II was the most widespread war in history, and countries involved mobilized more than 100 million military personnel. Total war erased the distinction between civil and military resources and saw the complete activation of a nation's economic, industrial, and scientific capabilities for the purposes of the war effort; nearly two-thirds of those killed in the war were civilians. For example, nearly 11 million of the civilian casualties were victims of the Holocaust, which was largely conducted in Eastern Europe, and the Soviet Union.
The conflict ended in an Allied victory. As a result, the United States and Soviet Union emerged as the world's two leading superpowers, setting the stage for the Cold War for the next 45 years. Self determination gave rise to decolonization/independence movements in Asia and Africa, while Europe itself began traveling the road leading to integration.
Course of the war:
In September 1931, Japan invaded Manchuria under false pretexts and captured it from the Chinese.
In 1933, Adolf Hitler of the Nazi Party became leader of Germany. Under the Nazis, Germany began to rearm and to pursue a new nationalist foreign policy. By 1937, Hitler also began demanding the cession of territories which had historically been part of Germany, like the Rhineland and Gdansk.
In July 1937, Japan launched a large scaled invasion of mainland China, beginning with the bombing of Shanghai and Guangzhou and followed by the Nanking massacre in December.
In Europe, Germany, and to a lesser extent Italy, asserted increasingly hostile and aggressive foreign policies and demands, which the United Kingdom and France initially attempted to diffuse primarily through diplomacy and appeasement.
In September 1939, Germany invaded Poland and war in Europe followed. The French and British did not declare war at first, hoping they could persuade Hitler through appeasement, but Hitler did not respond. The United Kingdom and France declared war. During the winter of 1939-1940 there was little indication of hostilities since neither side was willing to engage the other directly. This period was called the Phoney War.
In 1940, Germany captured Denmark and Norway in the spring, and then in the early
summer France and the Low Countries. The United Kingdom was then targeted; the Germans attempted to cut the island off from vitally needed supplies and obtain air superiority in order to make a seaborne invasion possible. This never came to pass, but the Germans continued to attack the British mainland throughout the war, primarily from the air. Unable to engage German forces on the continent, the United Kingdom concentrated on combating German and Italian forces in the Mediterranean Basin. It had limited success however; it failed to prevent the Axis conquest of the Balkans and fought indecisively in the Western Desert Campaign. It had greater success in the Mediterranean Sea, dealing severe damage to the Italian Navy, and dealt Germany's first major defeat by winning the Battle of Britain.In June 1941, the war expanded dramatically when Germany invaded the Soviet Union, bringing the Soviet Union into alliance with the United Kingdom. The German attack started strong, overrunning great tracts of Soviet territory, but began to stall by the winter.
Since invading mainland China and French Indochina in 1940, Japan had been subjected to increasing economic sanctions by the United States, Great Britain and Netherlands, and was attempting to reduce these sanctions through diplomatic negotiations. In December 1941, however, the war expanded again when Japan, already into its fifth year of war with China, launched near simultaneous attacks against the United States and British assets in Southeast Asia; four days later, Germany declared war on the United States. This brought the United States and Japan into the greater conflict and turned previously separate Asian and European wars into a single global one.
In 1942, though Axis forces continued to make gains, the tide began to turn. Japan suffered its first major defeat against American forces in the Battle of Midway, where four of Japan's aircraft carriers were destroyed. German forces in Africa were being pushed back by Anglo-American forces, and Germany's renewed summer offensive in the Soviet Union had ground to a halt.
In 1943 Germany suffered devastating losses to the Soviets at Stalingrad, and then again at Kursk, the greatest tank battle in military history. Their forces were expelled from Af
rica, and Allied forces began driving northward up through Sicily and Italy. The Japanese continued to lose ground as the American forces seized island after island in the Pacific Ocean.In 1944, the outcome of the war was becoming clearly unfavorable for the Axis. Germany became boxed in as the Soviet offensive became a juggernaut in the east, pushing the Germans out of Russia and pressing into Poland and Romania; in the west, the Western Allies invaded mainland Europe, liberating France and the Low Countries and reaching Germany's western borders. While Japan launched a successful major offensive in China, in the Pacific, their navy suffered continued heavy losses as American forces captured airfields within bombing range of Tokyo.
In 1945 the war ended. In Europe, a final German counter-attack in the west failed, while Soviet forces captured Berlin in May, forcing Germany to surrender. In Asia, American forces captured the Japanese islands of Iwo Jima and Okinawa while British forces in Southeast Asia managed to expel Japanese forces there. Initially unwilling to surrender, Japan finally capitulated after the Soviet Union invaded Manchukuo and the United States dropped atomic bombs on the mainland of Japan.
European Theatre:
In 1922, Italian dictator Benito Mussolini and his fascist party took control of the Kingdom of Italy and set the model for German dictator Adolf Hitler's Nazi Party, which, aided by the civil unrest caused by the Great Depression, took power in Germany and eliminated its democratic government, the Weimar Republic. These two leaders began to re-militarize their countries and become increasingly hostile. Mussolini first conquered the African nation of Abyssinia and then seized Albania, with both Italy and Germany actively supporting Francisco Franco's fascist Falange party in the Spanish Civil War against the Second Spanish Republic (which was supported by the Soviet Union). Hitler then broke the Treaty of Versailles by increasing the size of the Germany's military, and re-militarized the Rhineland. He started his own expansion by annexing Austria and sought the same against the German-speaking regions (Sudetenland) of Czechoslovakia.
The British and French governments followed a policy of appeasement in order to avoid military confrontation after the high cost of the First World War. This p
olicy culminated in the Munich Agreement in 1938, which would give the Sudetenland to Germany in exchange for Germany making no further territorial claims in Europe.[3][4] In March 1939, Germany annexed the remainder of Czechoslovakia. Mussolini, following suit, annexed Albania in April.The failure of the Munich Agreement pushed the United Kingdom and France to prepare for war with Germany. France and Poland pledged on May 19, 1939, to provide each other with military assistance in the event either was attacked. The following August, the British guaranteed the same.
On August 23, 1939, Germany and the Soviet Union signed the Molotov-Ribbentrop Pact which provided for sales of oil and food from the Soviets to Germany, thus reducing the danger of a British blockade such as the one that had nearly starved Germany in World War I. Also included was a secret agreement that would divide Central Europe into German and Soviet areas of interest, including a provision to partition Poland. Each country agreed to allow the other a free hand in its area of influence, including military occupation.
Germany's war against the Western Allies:
After Poland fell, Germany paused to regroup during the winter while the British and French stayed on the defensive. The period was referred to by journalists as "the Phoney War" because of the inaction on both sides. In Eastern Europe, the Soviets began occupying Baltic states leading to a confrontation with Finland, a conflict which ended with land concessions to the Soviets on March 12, 1940. In early April 1940, both German and Allied forces launched nearly simultaneous operations around Norway over access to Swedish iron ore. It was a two month campaign which resulted in complete German control of Denmark and Norway, though at a heavy cost to their surface navy. The fall of Norway led to the Norway Debate in London, which resulted in the resignation of Prime Minister Neville Chamberlain, who was replaced by Winston Churchill.
On May 10, 1940, the Germans invaded France and the Low Countries. The British Expeditionary Force (BEF) and the French Army advanced into Flanders and planned to fight a mobile war in the north, while maintaining a static continuous front along the Maginot Line further south. This was foiled by an unexpected German thrust through the Ardennes, splitting the Allies in two. The BEF and French forces, encircled in the north, were evacuated from Dunkirk in Operation Dynamo. France, overwhelmed by the blitzkrieg, was forced to sign an armistice with Germany on June 22, 1940, leading to the direct German occupation of Paris and two-thirds of France, and the establishment of a German puppet state headquartered in southeastern France known as Vichy France.
With only the United Kingdom remaining as an opposing force in Europe, Germany began to prepare Operation Sealion, the invasion of Britain. Most of the British Army's heavy weapons and supplies had been lost at Dunkirk, but the Royal Navy was still stronger than the Kriegsmarine and kept control of the English Channel. The Germans then attempted to gain air superiority by destroying the Royal Air Force (RAF) using the Luftwaffe. The ensuing air war in the late summer of 1940 became known as the Battle of Britain. The Luftwaffe initially targeted RAF Fighter Command aerodromes and radar stations, but Luftwaffe Commander Hermann Göring and Hitler, angered by British bombing raids on German cities, switched their attention towards bombing English cities, an offensive which became known as The Blitz. This diversion of resources allowed the RAF to rebuild their airbases, eventually leading Hitler to give up on his goal of establishing air superiority over the English Channel; this in turn led to the permanent postponing of Operation Sealion.
With Germany and her allies having total control of the continent, the United Kingdom and its allies settled for strategic bombing and special forces operations in mainland Europe. Many of the conquered nations formed governments in exile and military units within the United Kingdom as well as domestic resistance movements. Germany, meanwhile, fortified its position by constructing the Atlantic Wall.
Battle of the Atlantic:
With the German conquest of Norway and France by June 1940, U-boats enjoyed decreased resistance. The French Navy was removed as an Allied force, and additional ports in France on the Atlantic Ocean became available to the German Navy (Kriegsmarine), allowing them to increase the range of their vessels. The Royal Navy became severely stretched, having to remain stationed in the English Channel to protect against a German invasion, send forces to the Mediterranean Sea to make up for the loss of the French fleet, and provide escort for merchant vessels. This was somewhat mitigated by the Destroyers for Bases Agreement with the United States Navy in September 1940, in which the British exchanged several of their oversea bases for fifty destroyers which were then used for escort duties. The success of U-boats in this period led to an increase of their production and the development of the wolf pack technique.
The German surface navy, which had suffered substantial losses in the capture of Norway, had mixed results. While there were several successful merchant raids, such as Operation Berlin, they also suffered several losses, such as the heavy cruiser Graf Spee and battleship Bismarck. The loss of the Bismarck had deeper ramifications on naval policy though, because as a result Hitler ordered all heavy surface vessels to Norwegian waters[2], shifting them from raiding operations to protection from a potential Allied invasion of Scandinavia. While the Royal Navy also suffered the loss of capital ships, such as the aircraft carrier HMS Courageous, the battleship HMS Royal Oak and the battlecruiser HMS Hood, their larger surface navy was better able to absorb the losses.
Alarmed by the Italian setbacks, Hitler authorized reinforcements, and sent German forces to Africa in February. British Commonwealth leader started redeploying their forces, sending soldiers from North Africa to Greece starting in early March; in an effort to secure their transportation lines, the Allied navies managed to engage the Regia Marina in the Battle of Cape Matapan, doing significant damage to the Italian fleet. The German forces in Africa, led by German General Erwin Rommel, however, launched an offensive against the now depleted British Commonwealth forces near the end of March. During this offense, the Allies also feared having their oil supply cut due to a coup d'état in Iraq in early April. They were further pressed when the Germans invaded Greece and Yugoslavia. By the middle of April, Rommel's forces had pushed British Commonwealth forces forces back into Egypt with the exception of the port of Tobruk, which he encircled and besieged. Shortly after, the British responded to the coup in Iraq by invading and occupying the country. By the end of May, German forces had conquered Yugoslavia, mainland Greece and further captured the island of Crete, forcing a withdraw of all British Commonwealth forces from the Balkans.
In June 8, British Commonwealth and Free French forces invaded Vichy controlled Syria and Lebanon due to the Vichy allowance of Axis forces to pass through the area and utilize military bases. A week later, Wavell launched Operation Battleaxe, which was intended to be a major offensive in the Western Desert, but resulted in the loss of nearly half of the British Commonwealth tanks in the region. Frustrated by the lack of success, Churchill had Wavell replaced with Claude Auchinleck in early July. In late August, after the German invasion of the Soviet Union, the British and the Soviets launched a joint invasion of Iran to secure its oilfields and the Persian Corridor supply route for Soviet
There was then a lull in activity. The Soviet-German war had significantly reduced the importance of the Mediterranean theatre to the Germans and the British Commonwealth armies were re-grouping. On November 18, the Allies launched Operation Crusader, an offensive in the Western Desert which pushed Rommel back to his original starting point at El Agheila in Libya. The British suffered a significant blow in the sea though, losing several ships shortly after the First Battle of Sirte.
With the entry of Japan into the war in December 1941, the British Commonwealth forces were again forced to withdraw units in North Africa, transferring some to Burma. Once again Rommel took advantage of the situation, and on January 21, launched an offensive which pushed the British Commonwealth forces back to Gazala, just west of Tobruk. There was another lull in activity as both sides built up their forces. In May, after the Japanese Indian Ocean raid, British Commonwealth forces invaded Vichy controlled Madagascar to prevent the Imperial Japanese Navy from using as launch point for further such attacks. Rommel then launched his own attack in late May, overrunning the British position in the Western Desert and chasing them well into Egypt, being halted at El Alamein. Shortly after, the Royal Navy suffered significant damage getting much needed supplies to Malta.
Like Wavell before him, Auchinleck's perceived failures led to his replacement by Churchill, this time by Harold Alexander with Bernard Montgomery taking over Allied land forces in Egypt.
In late October, after building up his forces, Montgomery launched his offensive, pushing the Axis forces back and pursuing them across the desert. In November, Allied forces landed in Vichy-controlled Northwest Africa with minimal resistance; in retaliation, the Germans seized the remainder of mainland France, though they failed to capture the remainder of the French Navy. Soon, Rommel's forces were pincered in Tunisia and by May of 1943, were forced to evacuate Africa entirely.
In July, the Italian Campaign began with the Allied invasion of Sicily. The continued series of Italian defeats led to Mussolini being dismissed by the King of Italy, Victor Emmanuel III and subsequently arrested. His successor, Pietro Badoglio, then began negotiating surrender with the Allies. On September 3 the Allies invaded Italy itself and the Italians signed an armistice. This was made public on September 8, the same day the Allies launched a subsequent invasion of the Italian held Dodecanese islands. Germany had been planning for such an event though, and executed Operation Achse, the seizure of northern and central Italy. A few days later, Mussolini was rescued by German special forces and before the end of September created the Italian Social Republic, a German client state.
