World War II was the most extensive and costly armed conflict in the history of the world, involving the great majority of the world's nations, being fought simultaneously in several major theatres, and costing tens of millions of lives.
The German invasion of Poland on September 1, 1939 is the most common date in the West for the start of World War II. Others cite the Japanese invasion of China on July 7, 1937, as the war's beginning, or even the 1931 Japanese incursion into Manchuria. Still others cite that World War I and World War II are actually one conflict, and that the peace of the 1920s and early 30s merely served as a "ceasefire".
The war ended in Europe with the surrender of Nazi Germany on May 8, 1945 (V-E Day), but continued in Asia and the Pacific until the atomic bombing of Hiroshima and Nagasaki and the subsequent Japanese surrender on September 2, 1945 (V-J Day).
There are several main causes of this conflict, the most important being the unforeseen consequences of the Treaty of Versailles, which ended World War I, and the Great Depression, the worldwide economic disaster which gave rise to nationalism and militarism. The lead-up to the war stretches back to build-ups and smaller regional wars of the 1930s, which slowly drew in more countries and culminated in massive battles with millions of combatants in the first half of the 1940s.
Fighting occurred across the Atlantic Ocean, in the European theatre in and around eastern and western Europe, in North Africa and the Middle East as well as across the Mediterranean Sea, and in the Pacific theatre in the Pacific, in Oceania and across much of East Asia and South East Asia.
It was the first war in which air power was a significant factor and civilian suffering and terror a primary military strategy. The war caused more casualties than any war in history. This was partly due to its unprecedented scale, the first uses of mass aerial bombings against civilian populations, and the first application of industrial-age technology to enable the mass killing of unwanted civilians in extermination camps; a significant part of the German war machine was diverted towards the execution of Jews, Roma, Slavs and other unwanted citizens in the Holocaust. In total, World War II caused the deaths of about two percent of the population of the world.
The post-war period set the stage for the Cold War, with the Western Allies and most of Western Europe including West Germany, Italy, the United States and United Kingdom forming NATO, and the Soviet Union and its Eastern Europe satellites creating the Warsaw Pact. The struggle for dominance between these two alliances would last until the collapse of the Soviet Union in 1991. See Global effects of World War II.
See also List of World War II topics.
Note: There is currently an alternative writing of this article at World War II/temp.
Main article: Participants in World War II
Belligerents of the Second World War had aligned as two powers: the Axis and the Allies.
The Axis Powers consisted primarily of Germany, Italy, and Japan, which split the Earth into three spheres of influence under the Tripartite Pact of 1940, and vowed to defend one another against aggression. This replaced the German-Japanese Agreement and Anti-Comintern Pact of 1936. A number of smaller countries were part of the Axis powers. When Benito Mussolini's government was overthrown in 1945, Italy became an Allied power.
Among the Allied powers, the "Big Three" were the Soviet Union, the United Kingdom, and the United States. The British Commonwealth, Poland, France, Belgium, and the Netherlands were also members. For a complete list of members, see Participants.
Many countries, although avowedly neutral, provided military volunteers and other support either to the Allies or to the Axis.
Main article: Causes of World War II
The Second World War originated from a variety of causes. Some of the most commonly mentioned include the aggressive rise of totalitarian ideologies, and, from a narrower perspective, war reparations demanded of Weimar Germany after World War I, coupled with the effects of the Great Depression and the lack of raw materials in Japan.
The economic depression and inflation of these latter nations' currency contributed to the rise of fascist ideals and fervent nationalism, which, in turn, led to the militarization of the economy and mobilization of forces along key borders in these nations. With the rise of fascism, the foreign policies of the Axis nations became more aggressive and strained the Allied leadership.
Prelude to War
Main article: Events preceding World War II in Europe, Events preceding World War II in Asia
Resentment of the victorious powers' treatment of the Weimar Republic in the aftermath of World War I and economic difficulties caused by war reparations and the Great Depression allowed Adolf Hitler's extreme nationalist NSDAP movement to come to power in Germany. Due to the fragile political situation, Hitler was able to assume emergency powers and virtual total control of the country.
Defying post-WWI treaties, he re-developed the German military by means of the democratic constitution that was later put aside. He re-militarised the border zone next to France, enforced the re-unification with Austria in the so-called Anschluss, and with Franco-British acquiscence he annexed parts of Czechoslovakia.
Benito Mussolini ("Il Duce") with Adolf Hitler
In 1922 Benito Mussolini and the Fascist party had risen to power in Italy. Mussolini's Italian fascists shared some ideological goals with the German National Socialists or Nazis and, although Mussolini distrusted Hitler, the two countries formed an agreement that became known as the "Rome-Berlin Axis" in 1936.
In the east, Japan had, as early as the late nineteenth century, begun to spread out across Asia, brought about by conflict between traditional Japanese practices and changing social conditions associated with rapid industrialisation and modernisation. In 1905 Japan won an astounding victory over Russia, and in 1910 it occupied Korea and made it a colony.
During the 1920s democracy seemed to be taking root in Japan, but by the 1930s, the Great Depression brought to the fore many talented military leaders who took control of Japan, often ruling in the name of Emperor Hirohito, and playing on the traditional respect the Japanese people held for their emperors. In 1931, Japan invaded and occupied Inner Manchuria, setting up the puppet state of Manchukuo, and by 1937 launched a second invasion that occupied the rest of the region. For this reason, some scholars consider 1936/37 the actual start of World War II.
Main article: European Theatre of World War II, The end of World War II in Europe
War began in Europe on 1 September 1939 with the German invasion of Poland. France and the United Kingdom honored their defensive alliance of March 1939 by declaring war two days later on 3 September.1 Only partly mobilized, Poland fared poorly against the Wehrmacht's superior numbers and strategy of "blitzkrieg", which was used for the very first time. In accordance with the Molotov-Ribbentrop Pact, the Soviet Red Army invaded from the east on 17 September. Hours later, the Polish government escaped to Romania. The last Polish Army unit under the command of General Franciszek Kleeberg was defeated in the Battle of Kock on 6 October.
During the fall of Poland, the British and French remained largely inactive in what would be termed "the Phony War," lasting until May 1940. Isolated engagements occured during this period, including the sinking of the HMS Royal Oak in the British port of Scapa Flow and bombings of the naval bases at Rosyth and Scapa Flow by the Luftwaffe. The Kriegsmarine pocket battleship "Admiral Graf Spee" was sunk in South America after the battle of the River Plate.
The Tripartite Pact was signed between Germany, Italy, and Japan on 27 September, 1940, formalizing their alignment as the "Axis Powers."
Finland was invaded by the Soviet Union on 30 November 1939, beginning the Winter War, which lasted until March of 1940 with Finland ceding territory to the Soviet Union. On 9 April, 1940, Germany invaded Denmark and Norway in Operation WeserŘbung, ostensibly for the threat of an Allied invasion from the region. Heavy fighting ensued on land and at sea in Norway. British, French and Polish forces landed to support the Norweigans, at Namsos, ┼ndalsnes and Narvik, with more success at the latter (see Namsos in April 1940). But, by early June all Allied forces were evacuated and the Norweigan army surendered.
France and the Low Countries were invaded on 10 May, ending the Phony War. In the first phase of the invasion, Operation Yellow, the Wehrmacht's Panzergruppe von Kleist bypassed the Maginot Line and split the Allies in two by driving to the English channel. Belgium, Luxembourg, and the Netherlands fell quickly against the attack of Army Group B and the British Expeditionary Force, trapped in the north, was evacuated at Dunkirk in Operation Dynamo. German forces then invaded France itself, in Operation Red, advancing behind the Maginot Line and near the coast. Defeated, an armistice was declared on 22 June and the Vichy France puppet government created.
In June of 1940 the Soviet Union occupied Latvia, Lithuania, and Estonia, and annexed Bessarabia and Northern Bukovina from Romania.
Not having secured a rapid peace with the United Kingdom, as desired, Germany began preparations to invade with the Battle of Britain. Fighter aircraft fought overhead for months as the Luftwaffe and Royal Air Force fought for control of Britain's skies. The Luftwaffe initially targetted RAF Fighter Command, however it turned to terror bombing London. Germany was defeated and Operation Sealion, the proposed invasion of the British Isles, was abandoned. Similar efforts were made, though at sea, in the Battle of the Atlantic. In a long-running campaign, German U-Boats attempted to deprive the British Isles of necessary Lend Lease cargo from the United States. Shipments were reduced considerably by the U-Boats, however it was not sufficient to cause the United Kingdom to seek peace.
Italy invaded Greece on 28 October, 1940. Greek forces, however, succesfully repelled the Italian attacks marking the first Allied nation victory. A reluctant Hitler then sent forces to assist Mussolini by invading Greece in April of 1941, principally to prevent a British buildup on Germany's strategic southern flank. Greece was attacked by Italian, German, Hungarian, and Bulgarian troops. German troops faced fierce civilian resistance in their effort to ocupy the island of Crete seized Crete in a parachute drop.The operation was over by April, 1941.
Operation Barbarossa, the German invasion of the Soviet Union, commenced on 22 June 1941. The "Great Patriotic War" (Russian: Великая Отечественная Война, Velikaya Otechestvennaya Voyna) had begun with surprise attacks by German panzer armies, which encircled and destroyed much of the Soviet's western military, capturing or killing hundreds of thousands of men. Soviet forces came to fight a war of scorched earth, withdrawing into the steppe of Russia to acquire time and stretch the German army. Industries were dismantled and withdrawn to the Ural mountains for reassembling. German armies pursued a three-pronged advance against Leningrad, Moscow, and the Caucasus. Having pushed to occupy Moscow before winter, German forces were delayed into the Soviet Winter. Soviet counterattacks defeated them within sight of Moscow's spires, and a rout was only narrowly avoided. This is identified by some historians as the "turning point" in the Allies' war against Germany; others identify the capitulation of German Sixth Army outside Stalingrad in 1943.
The Continuation War between Finland and the Soviet Union began shortly after the beginning of Operation Barbarossa, on 25 June, and ended with an armistice in 1944.
Germany declared war on the United States on 11 December 1941, following the Japanese attack on Pearl Harbor. It was not obligated to do so under the Tripartite Pact of 1940. Hitler made the declaration in the hopes that Japan will support him by attacking the Soviet Union. Japan did not oblige him and this diplomatic move proved a catastrophic blunder which gave Franklin Roosevelt the pretext he needed for the USA to join the fight in Europe with full commitment with no meaningful opposition in congress. Some historians mark this moment as another major turning point of the war with Hitler provoking a grand alliance of powerful nations who could wage powerful attacks on both East and West simultaneously.
In 1942, an aborted German offensive was launched towards the Caucasus to secure oil fields and German armies reached Stalingrad. The siege of Stalingrad lasted into February of 1943, resulting in the destruction of the city, millions of casualties, and the surrender of Germany's Sixth Army. Nazi Propaganda Minister Joseph Goebbels responded with his Sportpalast speech to the German people. This is cited by some historians as the European war's "turning point."
Red Army offensives along the Don basin near Stalingrad were repulsed by German forces in January 1943. In July, the Wehrmacht launched a much-delayed offensive against the Soviet Union at Kursk. Their intentions were known by the Soviets, and the Battle of Kursk ended in a Soviet counteroffensive which threw the German Army back.
North Africa was used as a springboard for the invasion of Sicily on 10 July 1943. Having captured Sicily, the Allies invaded mainland Italy on 3 September 1943. Shortly before the main invasion of 8 September, the Italian government surrendered. The German Army continued to fight from the Gothic Line and then Winter Line in Italy's mountains. The conflict would last until the spring of 1945.
German-held Normandy was invaded on 6 June 1944 ("D-Day") by the Westen Allies, opening the "second front" against Germany.2 Hedgerows aided the defender, and for months the Allies measured progress in hundreds of yards. An Allied breakout was effected at St.-L˘, and the most powerful German force in France, the Seventh Army was destroyed in the Falaise pocket while counterattacking. The French Riviera was invaded by Allied forces stationed in Italy on 15 August, and linked up with forces from Normandy. Paris was captured by the Allies on 25 August.
Shortly after Allied landings at Normandy, 9 June, the Soviet Union began an offensive on the Karelian Isthmus, that after three months would force Nazi Germany's co-belligerent Finland to an armistice. Operation Bagration, a Soviet offensive involving 2.5 million men and 6,000 tanks, was launched on 22 June, destroying the German Army Group Centre and taking 350,000 prisoners. By early 1944, the Red Army had reached the border of Poland and lifted the Siege of Leningrad.
Romania surrendered in August of 1944 and Bulgaria in September. British forces attempted a fast advance into Germany with Operation Market Garden in September, but were repulsed. The Warsaw Uprising was fought between 1 August and 2 October. Germany withdrew from the Balkans and held Hungary until February 1945.
In December of 1944, the German Army made its last major offensive in the West, attempting to capture the vital port of Antwerp and cripple the Allies in the Battle of the Bulge. The offensive was defeated. By now, the Soviets had reached the eastern borders of pre-war Germany.
The Red Army began its final assault on Berlin on 16 April. Hitler and his staff moved into a bunker beneath the Chancellery, where on 30 April 1945 he committed suicide. Admiral Karl D÷nitz had been appointed President of Germany by Hitler, and unconditionally surrendered on 8 May, marking the end of the European war and "VE Day."3
US landing in the Pacific, August 1942-August 1945
Main article: Pacific War
In 1940, Japan occupied French Indochina (Vietnam) upon agreement with the Vichy Government and despite local Free French, and joined the Axis powers Germany and Italy. These actions intensified Japan's conflict with the United States and the United Kingdom which reacted with an oil boycott.
The Japanese had already invaded China before World War II started in Europe. U.S. President Roosevelt signed an executive order in May of 1940 allowing U.S. military personnel to resign from the service so that they could participate in a covert operation in China. Hence was born the All Volunteer Group, more commonly known as Chennault's Flying Tigers. With the United States and other countries cutting exports to Japan, Japan decided to bomb Pearl Harbor on 7 December 1941 without warning or declaration of war. Severe damage was done to the American Pacific Fleet, although the aircraft carriers escaped as they were at sea. Japanese forces simultaneously invaded the British possessions of Malaya and Borneo and the American occupied Philippines, with the intention of seizing the oilfields of the Dutch East Indies. The British island fortress of Singapore was captured in what Churchill considered one of the most humiliating British defeats of all time.
In May 1942, the Allied navies in the Battle of the Coral Sea thwarted a Japanese naval attack on Port Moresby, New Guinea which had it succeeded would have put them within striking range of Australia. This was both the first successful opposition to Japanese plans and the first naval battle fought only between aircraft carriers. A month later the U.S. Navy again prevented the invasion of Midway Island, this time destroying four Japanese carriers, which Japanese industry could not replace, and putting the Japanese navy on the defensive.
However, in July the Japanese Army attempted an overland attack on Port Moresby, along the rugged Kokoda Track. Australian reservists, many of them very young and untrained, fought a stubborn rearguard action, until they were relieved by Australian regular troops returning from action in the Middle East.
The Allied leaders had agreed even prior to the American entry to the war that priority should be given to the defeat of Nazi Germany. Nonetheless US and Australian forces under General Douglas MacArthur began to attack captured territories, beginning with, against the bitter and determined defence of Japanese troops, Guadalcanal Island. On 7 August 1942 the island was assaulted by United States Marines. In late August and early September, while battle raged on Guadalcanal, Australian forces fought off a Japanese amphibious attack on the eastern tip of New Guinea at Milne Bay, the first conclusive defeat suffered by Japanese land forces. US forces triumphed on Guadalcanal in February 1943.
Exhausted Australian and US forces then strove to retake the occupied parts of New Guinea and the Dutch East Indies, experiencing some of the toughest resistance of the Pacific Theatre. The rest of the Solomon Islands were retaken in 1943, New Britain and New Ireland in 1944. The Philippines were attacked in late 1944 following the Battle of Leyte Gulf.
US and Allied submarines and aircraft also attacked Japanese merchant shipping, depriving Japanese industry of the raw materials she had gone to war to obtain. The effectiveness of this stranglehold increased as the U.S. captured islands closer to the Japanese mainland.
The Nationalist Kuomintang Army under Chiang Kai-shek and the Communist Chinese Army under Mao Zedong both opposed the Japanese occupation of China, but never truly allied against the Japanese. Conflict between Nationalist and Communist forces continued after and, to an extent, even during the war.
The Japanese captured most of Burma severing the Burma Road by which the Western Allies had been supplying the Chinese Nationalists. This forced the Allies to create a large sustained airlift of the war known as the Hump. US lead and trained Chinese divisions, a few thousand US ground forces and a British Division, cleared the Japanese forces from northern Burma so that the Ledo Road could be built to replace the Burma Road. Further south the main Japanese army in the theater were fought to a standstill on the Burma India frontier by the British Fourteenth Army (the "forgotten" army) which then counter-attacked and having recaptured all of Burma was planning attacks towards Malaya when the war ended.
Japanese surrender abord the USS-Missouri at Tokyo Bay
Capture by the Allies of islands such as Iwo Jima and Okinawa close to Japan brought the homeland within range of naval and air attacks, Tokyo was firebombed and later an atomic bomb, the "Little Boy", was dropped from the B-29 "Enola Gay" and destroyed Hiroshima. On 8 August 1945 the Soviet Union declared war on Japan, as had been agreed to at Yalta, and launched a large scale invasion of Japanese occupied Manchuria (operation August Storm). On August 9, in Nagasaki, another atom bomb, "Fat Man" was dropped by the B-29 "Bock's Car".
The Japanese surrendered on 14 August 1945, signing official surrender papers on 2 September 1945 aboard the USS Missouri in Tokyo Bay.
African and Middle Eastern Theatre
The North African Campaign began in 1940, when small British forces in Egypt turned back an Italian advance from Libya. This advance was stopped in 1941 when German forces under Erwin Rommel landed in Libya. In addition, in June 1941 the Australian Army and allied forces invaded Syria and Lebanon, capturing Damascus on 17 June. Rommel's Afrika Korps advanced rapidly eastward, laying siege to the vital seaport of Tobruk. The Australian and British troops in the city resisted all until relieved, but a renewed Axis offensive captured the city and drove the Eighth Army back to a line at El Alamein.
The First Battle of El Alamein took place between July 1 and July 27, 1942. German forces had advanced to the last defensible point before Alexandria and the Suez Canal. However they had outrun their supplies, and a British and Commonwealth defence stopped their thrusts. The Second Battle of El Alamein occurred between October 23 and November 3, 1942 after Bernard Montgomery had replaced Claude Auchinleck as commander of the Eighth Army. Commonwealth forces took the offensive and destroyed the Afrika Korps. Rommel was pushed back, and this time did not stop falling back until Tunisia.
To complement this victory, on 8 November 1942, American and British troops landed in Morocco and Algeria in Operation Torch. The local forces of Vichy France put up limited resistance before joining the Allied cause. Ultimately German and Italian forces were caught in the pincers of a twin advance from Algeria and Libya. Advancing from both the east and west, the Allies completely pushed the Wehrmacht out of Africa and on May 13, 1943, the remnants of the Axis forces in North Africa surrendered. 250,000 prisoners were taken; as many as at Stalingrad.
North Africa was used as the jumping-off point for the invasions of Sicily and mainland Italy in 1943.
In contrast to World War I, the Western victors in the Second World War did not demand compensation from the defeated nations. On the contrary, a plan created by U. S. Secretary of State George Marshall, the "European Recovery Program", better known as the Marshall Plan, called for the U.S. Congress to allocate billions of dollars for the reconstruction of Europe. Also as part of the effort to rebuild global capitalism and spur post-war reconstruction, the Bretton Woods system was put into effect after the war.
Since the League of Nations had obviously failed to prevent the war, a new international order was constructed. In 1945 the United Nations was founded. Also, in order to prevent such devastating war from occurring again and to establish a lasting peace in Europe, the European Coal and Steel Community was born in 1951 (Treaty of Paris (1951)), which became the predecessor of the European Union.
The future Warsaw Pact countries did not subscribe to the Marshall Plan. In the Paris Peace Treaty, the Soviet Union's enemies Hungary, Finland and Romania were required to pay war reparations of $300,000,000 each (in 1938 dollars) to the USSR. Italy was required to pay $360,000,000, shared chiefly between Greece, Yugoslavia and the Soviet Union.
In the areas occupied by Western Allied troops, capitalist governments were created, in the areas occupied by Soviet troops, communist governments were created. Germany was partitioned into four zones of occupation, with the American, British and French zones grouped as West Germany and the Soviet zone as East Germany. Austria was once again separated from Germany and it, too, was divided into four zones of occupation which eventually re-united and became the state of Austria. The Cold War had begun, and soon NATO and the Warsaw Pact would form.
The repatriation, pursuant to the terms of the Yalta Conference, of two million Russian soldiers who had come under the control of advancing American and British forces, resulted for the most part in their deaths.
The massive research and development involved in the Manhattan Project in order to quickly achieve a working nuclear weapon design greatly impacted the scientific community, among other things creating a network of national laboratories in the United States. In addition, the pressing for numerous calculations for various things like code breaking and ballistics tables kickstarted the development of electronic computer technology.
In the military sphere, World War II marked the coming of age of airpower, mostly at the expense of warships. While the pendulum continues to swing in this never-ending competition, air powers are now a full partner in any military action. World War II also saw the creation of guided missiles which, like airpower, are now used in virtually every conflict.
The war was the high-water mark for mass armies. While huge armies of low-quality troops would be seen again (during the Korean War and in a number of African conflicts), after this victory the major powers relied upon small highly-trained and well-equipped militaries.
After the war, many high-ranking Germans were prosecuted for war crimes, as well as the mass murder of the Holocaust committed mainly on the area of General Government, in the Nuremberg trials. Similarly Japanese leaders were prosecuted in the Tokyo War Crime Trial.
Although pursuant to Article XXII of the draft Hague Rules of Air Warfare 1923, "aerial bombardment for the purpose of terrorizing the civilian population, of destroying or damaging private property not of a military character, or of injuring non-combatants" was to be prohibited, these rules had never been ratified by the Powers. Some attempt was made to adhere to the rules in the early part of the war by some of the participants. In the first months of the war the RAF was for example ordered by the British Government to adhere strictly to the draft rules, but this restriction was progessively relaxed, and abandonned altogether in 1942. By 1945 the stratiegic bombing of cities had been employed extensively by all sides, most notably in Poland, Britain, Germany and Japan, and no action was taken against those responsible.
In other countries, notably in Finland, the Allies demanded the political leadership to be prosecuted in "war-responsibility trials" — i.e. not for crimes of war.
The defeat of Japan, and its occupation by American Forces, led to a westernization of Japan that was surely more far-reaching than would otherwise have occurred. Japan approximated more closely to a Western style democracy and, because of its defeat by the USA, set out to imitate the United States. This huge national effort led to the post-war Japanese economic miracle and Japan's rise to become the world's second largest economy. It is also interesting to note that Germany, the other defeated country in WWII, is currently the world's third largest economy right behind the United States and Japan yet ahead of the victors of WWII including Great Britain, Russia, Australia, Canada, France, and many more.
The destruction of Europe and the destruction, via aerial bombing, of a significant proportion of the United Kingdom's cities would also symbolically destroy the aura of invincibility the European nation had in the eyes of their colonies. Coupled with the enormous amount of money it had expended during the war, an empire was perceived to be an unnecessarily expensive possession. Thus this would provoke the rapid decolonisation process that would see the empires of the United Kingdom, France, Netherlands, Portugal and others swept away.