World War II.html



World War II
Clockwise from top left: Commonwealth troops in the desert; Chinese civilians being buried alive by Japanese soldiers; Soviet forces during a winter offensive; Carrier-borne Japanese planes readying for take off; Soviet troops fighting in Berlin; A German submarine under attack.
Date September 1, 1939 – September 2, 1945 Location Europe, Pacific, South-East Asia, China, Middle East, Mediterranean and Africa Result Allied victory. Creation of the United Nations. Emergence of the United States and the Soviet Union as superpowers. Creation of First World and Second World spheres of influence in Europe leading to the Cold War. (more...)
Belligerents
Allies	Axis powers
Commanders
Allied leaders	Axis leaders
Casualties and losses
Military dead: Over 14,000,000 Civilian dead: Over 36,000,000 Total dead: Over 50,000,000 ...further details.	Military dead: Over 8,000,000 Civilian dead: Over 4,000,000 Total dead Over 12,000,000 ...further details.

World War II, or the Second World War,^[1] (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including all of the great powers,^[2] organized into two opposing military alliances: the Allies and the Axis. The war involved the mobilization of over 100 million military personnel, making it the most widespread war in history. In a state of "total war", the major participants placed their complete economic, industrial, and scientific capabilities at the service of the war effort, erasing the distinction between civilian and military resources. Over 70 million people, the majority of them civilians, were killed, making it the deadliest conflict in human history.^[3] The total financial cost of the war is estimated at about US$1 trillion,^{clarify[4][5]} making it the most expensive war as well.^[6]

The starting date of the war is generally held to be September 1939 with the German invasion of Poland and subsequent declarations of war on Germany by the United Kingdom, France and the British Dominions;^[7][8] some sources use other starting points, including the Mukden Incident, the Marco Polo Bridge Incident, and the Attack on Pearl Harbor. The Allies were victorious, with Germany surrendering on May 8, 1945 and Japan on September 2.

The Soviet Union and the United States emerged as the world's leading superpowers. This set the stage for the Cold War, which lasted for the next 45 years. The United Nations was formed in the hope of preventing another such conflict. The self determination spawned by the war accelerated decolonization movements in Asia and Africa, while Western Europe itself began moving toward integration.

Background

Main article: Causes of World War II

In the aftermath of World War I, a defeated Germany signed the Treaty of Versailles.^[9] This caused Germany to lose a significant portion of its territory, prohibited the annexation of other states, limited the size of German armed forces and imposed massive reparations. Russia's Civil war led to the creation of the Soviet Union which soon was under the control of Joseph Stalin. In Italy, Benito Mussolini seized power as a fascist dictator promising to create a "New Roman Empire."^[10] The ruling Kuomintang (KMT) party in China launched a unification campaign against rebelling warlords in the mid-1920s, but was soon embroiled in a civil war against its former Chinese communist allies. In 1931, an increasingly militaristic Japanese Empire, which had long sought influence in China^[11] as the first step of its right to rule Asia, used the Mukden Incident as justification to invade Manchuria; the two nations then fought several small conflicts until the Tanggu Truce in 1933.

German troops at the 1935 Nuremberg Rally.

National Socialist Adolf Hitler became the leader of Germany in 1933 and soon began a massive rearming campaign.^[12] This worried France and the United Kingdom, who had lost much in the previous war, as well as Italy, which saw its territorial ambitions threatened by those of Germany.^[13] To secure its alliance, the French allowed Italy a free hand in Ethiopia, which Italy desired to conquer. The situation was aggravated in early 1935 when the Saarland was legally reunited with Germany and Hitler repudiated the Treaty of Versailles, speeding up remilitarization and introducing conscription. Hoping to contain Germany, the United Kingdom, France and Italy formed the Stresa Front. The Soviet Union, concerned due to Germany's goals of capturing vast areas of eastern Europe, concluded a treaty of mutual assistance with France.

Before taking effect though, the Franco-Soviet pact was required to go through the bureaucracy of the League of Nations, rendering it essentially toothless^[14][15] and in June of 1935, the United Kingdom made an independent naval agreement with Germany easing prior restrictions. The United States, concerned with events in Europe and Asia, passed the Neutrality Act in August.^[16] In October, Italy invaded Ethiopia, with Germany the only major European nation supporting her invasion. Italy then revoked objections to Germany's goal of making Austria a satellite state.^[17]

In direct violation of the Versailles and Locarno treaties, Hitler remilitarized the Rhineland in March of 1936. He received little response from other European powers.^[18] When the Spanish Civil War broke out in July, Hitler and Mussolini supported fascist Generalísimo Francisco Franco's nationalist forces in his civil war against the Soviet-supported Spanish Republic. Both sides used the conflict to test new weapons and methods of warfare^[19] and the nationalists would prove victorious in early 1939.

With tensions mounting, efforts to strengthen or consolidate power were made. In October, Germany and Italy formed the Rome-Berlin Axis and a month later Germany and Japan, each believing communism and the Soviet Union in particular to be a threat, signed the Anti-Comintern Pact, which Italy would join in the following year. In China, the Kuomintang and communist forces agreed on a ceasefire to present a united front to oppose Japan.^[20]

Chronology

Other dates for the beginning of war include the Japanese invasion of Manchuria in 1931,^[21][22] the start of the Second Sino-Japanese War in 1937,^[23][24] or one of several other events. Other sources follow A. J. P. Taylor, who holds that there was a simultaneous Sino-Japanese War in East Asia, and a Second European War in Europe and her colonies, but they did not become a World War until they merged in 1941; at which point the war continued until 1945. This article uses the conventional dating.^[25]

The end of the War also has several dates. Some sources end it from the armistice of August 14, 1945, rather than the formal surrender; in some European histories, it ended on V-E Day. The Treaty of Peace with Japan was not signed until 1951.

Course of the war

See also: Timeline of World War II

War in China

Japanese forces during the Battle of Wuhan.

In mid-1937, following the Marco Polo Bridge Incident, Japan began a full invasion of China. The Soviets quickly lent support to China, effectively ending China's prior cooperation with Germany. Starting at Shanghai, the Japanese pushed Chinese forces back, capturing the capital Nanjing in December. In June of 1938 Chinese forces stalled the Japanese advance by flooding the Yellow River; though this bought time to prepare their defenses at Wuhan, the city was still taken by October.^[26] During this time, Japanese and Soviet forces engaged in a minor skirmish at Lake Khasan; in May of 1939, they became involved in a more serious border war^[27] that ended with signing a cease-fire agreement on 15 September and restoring the status quo ante bellum.^[28]

War breaks out in Europe

In Europe, Germany and Italy were becoming bolder. In March 1938, Germany annexed Austria, again provoking little response from other European powers.^[29] Encouraged, Hitler began making claims on the Sudetenland; France and Britain conceded these for a promise of no further territorial demands.^[30] Germany soon reneged. In March 1939 Germany and Hungary fully occupied Czechoslovakia..

Alarmed, and with Hitler making further demands on Danzig, France and Britain guaranteed their support for Polish independence; when Italy conquered Albania in April, the same guarantee was extended to Romania and Greece.^[31] The Soviet Union also attempted to ally with France and Britain, but was rebuffed due to western suspicions about Soviet motives and capability.^[32] Shortly after the Franco-British pledges to Poland, Germany and Italy formalized their own alliance with the Pact of Steel.
Understanding that France and Britain are unwilling to create a formal military alliance with USSR^[33] and apprehension that it might be a war between Hitler and the USSR with the Western powers neutral or tacitly favorable to Hitler^[34], the Soviet Union signed a non-aggression pact with Germany, including a secret agreement to split Poland and Eastern Europe between them.^[35]

Soviet and German officers in Poland.

On September 1, 1939, Adolf Hitler launched his invasion of Poland and World War II broke out. France, Britain, and the countries of the Commonwealth declared war on Germany but lent little support other than a small French attack into the Saarland.^[36] In mid-September, after signing an armistice with Japan, the Soviets launched their own invasion of Poland.^[37] By early October, Poland had been divided between Germany and the Soviet Union. During the battle in Poland, Japan launched its first attack against Changsha, a strategically important Chinese city, but was repulsed by early October.^[38]

Following the invasion of Poland, the Soviet Union began moving troops into the Baltic States. Finnish resistance to similar pressure by the Soviet Union in late November led to the four-month Winter War, ending with Finnish concessions.^[39] France and the United Kingdom, treating the Soviet attack on Finland as tantamount to entering the war on the side of the Germans^[40] responded to the Soviet invasion by supporting its expulsion from the League of Nations.^[40] Though China had the authority to veto such an action, it was unwilling to alienate itself from either the Western powers or the Soviet Union and instead abstained.^[40] The Soviet Union was displeased by this course of action and as a result suspended all military aid to China.^[40] By June 1940, the Soviet Armed Forces completed the occupation of the Baltic States.^[41]

German troops in Paris after the fall of France.

In Western Europe, British troops deployed to the Continent, but neither Germany nor the Allies launched direct attacks on the other. In April, Germany invaded Denmark and Norway to secure shipments of iron-ore from Sweden which the allies would try to disrupt. Denmark immediately capitulated, and despite Allied support, Norway was conquered within two months.^[42] British discontent over the Norwegian campaign led to the replacement of Prime Minister Neville Chamberlain by Winston Churchill on May 10, 1940.^[43]

Axis advances

On that same day, Germany invaded France and the Low Countries. The Netherlands and Belgium were overrun using blitzkrieg tactics in a few weeks. The French fortified Maginot Line was circumvented by a flanking movement through the Ardennes mountains, mistakenly perceived by France as an impenetrable natural barrier against armored vehicles. British troops were forced to evacuate the continent at Dunkirk, abandoning their heavy equipment by the end of the month.^[44] On June 10th, Italy invaded, declaring war on both France and the United Kingdom;^[44] twelve days later France surrendered and was soon divided into German and Italian occupation zones,^[45] and an unoccupied rump state under the Vichy Regime. In early July, the British attacked the French fleet in Algeria to prevent their seizure by Germany.^[46]

RAF Supermarine Spitfire during the Battle of Britain.

With France neutralized, Germany began an air superiority campaign over Britain to prepare for an invasion^[47]. The campaign failed and by September the invasion plans were cancelled. Using newly-captured French ports the German Navy enjoyed success against an over-extended Royal Navy, using U-boats against British shipping in the Atlantic.^[48] Italy began operations in the Mediterranean, initiating a siege of Malta in June, conquering British Somaliland in August, and making an incursion into British-held Egypt in early September. Japan increased its blockade of China in September by seizing several bases in the northern part of the now-isolated French Indochina.^[49]

Throughout this period, the neutral United States took measures to assist China and the Western Allies. In November 1939, the American Neutrality Act was amended to allow Cash and carry purchases by the Allies.^[50] In 1940, following the German capture of Paris, the size of United States Navy was significantly increased and after the Japanese incursion into Indochina, the United States embargoed iron, steel and mechanical parts against Japan.^[51] In September, the United States further agreed to a trade of American destroyers for British bases.^[52]

At the end of September the Tripartite Pact between Japan, Italy and Germany formalized the Axis Powers. The pact stipulated, with the exception of the Soviet Union, any country not in the war which attacked any Axis Power would be forced to go to war against all three.^[53] The Soviet Union expressed interest in joining the Tripartite Pact, sending a modified draft to Germany in November and offering a very German-favourable economic deal;^[54] while Germany remained silent on the former, they accepted the latter.^[55] Regardless of the pact, the United States continued to support the United Kingdom and China by introducing the Lend-Lease policy^[56] and creating a security zone spanning roughly half of the Atlantic Ocean where the United States Navy protected British convoys.^[57]

In October, Italy invaded Greece but within days were repulsed and pushed back into Albania, where a stalemate soon occurred.^[58] Shortly after this, in Africa, Commonwealth forces launched offensives against Egypt and Italian East Africa. By early 1941, with Italian forces having been pushed back into Libya by the Commonwealth, Churchill ordered a dispatch of troops from Africa to bolster the Greeks. The Italian Navy also suffered significant defeats, with the Royal Navy putting three Italian battleships out of commission via carrier attack at Taranto, and several more warships neutralized at Cape Matapan.^[59]

German paratroopers invading Crete.

The Germans soon intervened to assist Italy. Hitler sent German forces to Libya in February and by the end of March they had launched an offensive against the diminished Commonwealth forces. In under a month, Commonwealth forces were pushed back into Egypt with the exception of the besieged port of Tobruk. The Commonwealth attempted to dislodge Axis forces in May and again in June, but failed on both occasions. In early April the Germans similarly intervened in the Balkans, invading Greece and Yugoslavia; here too they made rapid progress, eventually forcing the Allies to evacuate after Germany conquered the Greek island of Crete by the end of May.^[60]

The Allies did have some successes during this time though. In the Middle East, Commonwealth forces first quashed a coup in Iraq which had been supported by German aircraft from bases within Vichy-controlled Syria,^[61] then, with the assistance of the Free French, invaded Syria and Lebanon to prevent further such occurrences.^[62] In the Atlantic, the British scored a much needed public morale boost by sinking the German flagship Bismarck.^[63] Perhaps most importantly, during the Battle of Britain the Royal Air Force had successfully resisted the Luftwaffe's assault, and on May 11, 1941, Hitler called off the bombing campaign.^[64]

In Asia, in spite of several offensives by both sides, the war between China and Japan was stalemated by 1940. In August of that year, Chinese communists launched an offensive in Central China; in retaliation, Japan instituted harsh measures in occupied areas to reduce human and material resources for the communists.^[65] Mounting tensions between Chinese communist and nationalist forces culminated in January 1941, effectively ending their co-operation.^[66]

With the situation in Europe and Asia relatively stable, Germany, Japan and the Soviet Union made preparations. With the Soviets wary of mounting tensions with Germany and the Japanese planning to take advantage of the European War by seizing resource-rich European possessions in Southeast Asia the two powers signed a neutrality agreement in April, 1941.^[67] By contrast the Germans were steadily making preparations for an attack on the Soviet Union, amassing forces on the Soviet border.^[68]

The war becomes global

German soldiers in the Invasion of the Soviet Union, 1941.

In late June, Germany, along with other European Axis members and Finland, invaded the Soviet Union. They made significant gains into Soviet territory, inflicting large numbers of casualties, and by the start of December had almost reached Moscow, with only the besieged cities of Leningrad and Sevastopol behind their front-lines left unconquered.^[69] With the onset of a fierce Soviet winter though, the Axis offensive was ground to a halt^[70] and the Soviets launched a counter-offensive using reserve troops brought up from the border near Japanese Manchukuo.^[71]

Following the German attack on the Soviets, the United Kingdom began to regroup. In July, the United Kingdom and the Soviet Union formed a military alliance against Germany^[72] and shortly after jointly invaded Iran to secure the Persian Corridor and Iran's oilfields.^[73] In August, the United Kingdom and United States jointly issued the Atlantic Charter, a vision for a post-war world which included "the right of all peoples to choose their form of government".^[74] In November, Commonwealth forces launched a counter-offensive in the desert, reclaiming all gains the Germans and Italians had made.^[75]

Japan, hoping to utilize Germany's control over the Netherlands, made several demands, including a steady supply of oil, from the Dutch East Indies; these talks, however, broke down in June.^[76] In July, Japan seized military control of southern Indochina since it would not only put them in a better position to coerce the Dutch East Indies into yielding, but it would also be a blow against China; should war be necessary, it also improved their strategic position against the Americans and British.^[77] The United States, United Kingdom and other western governments responded to Japan's incursion by freezing all Japanese assets^[78] and the United States, which supplied 80% of Japan's oil, further placed an oil embargo against Japan.^[79] With the unexpected embargo, Japan was essentially forced to choose between withdrawing from their aggression in Asia, or seizing the oil they needed directly; the Japanese military did not consider the former an option, and many of them considered the oil embargo as an unspoken declaration of war.^[80]

The Imperial General Headquarters thus planned to create a large perimeter stretching into the Central Pacific in order to facilitate a defensive war while exploiting the resources of Southeast Asia; to prevent intervention while securing the perimeter it was further planned to neutralize the United States Pacific Fleet on the outset.^[81] On December 7th Japan attacked British, Dutch and American holdings with near simultaneous offensives against Southeast Asia and the Central Pacific, including an attack on the American naval base of Pearl Harbor.^[82]

These attacks prompted the United States, United Kingdom, China, and other Western Allies to declare war on Japan. Italy, Germany, and the other members of the Tripartite Pact responded by declaring war on the United States. In January, the United States, United Kingdom, Soviet Union and China, along with twenty-two smaller or exiled governments, issued the Declaration by United Nations, affirming the Atlantic Charter^[83] and formalizing their alliance against the Axis Powers. The Soviet Union did not adhere fully to the declaration though, as they maintained their neutrality agreement with Japan^[84] and exempted themselves from the principle of self-determination.^[74]

British troops at the Battle of El Alamein in Egypt.

The Axis Powers, however, were able to continue their offensives. Japan had almost fully conquered Southeast Asia with minimal losses by the end of April, 1942, chasing the Allies out of Burma and taking large numbers of prisoners in the Philippines, Malaya, Dutch East Indies and Singapore.^[85] They further bombed the Allied naval base at Darwin, Australia and sunk significant Allied warships not only at Pearl Harbor, but also in the South China Sea, Java Sea and Indian Ocean.^[86] The only real successes against Japan were a repulsion of their renewed attack on Changsha in early January, 1942,^[87] and a psychological strike from a bombing raid on Japan's capital Tokyo in April.^[88]

Germany was able to regain the initiative as well. Exploiting American inexperience with submarine warfare, the German Navy sunk significant resources near the American Atlantic coast.^[89] In the desert, they launched an offensive in January, pushing the British back to positions at the Gazala Line by early February.^[90] In the Soviet Union, the Soviet's winter counter-offensive had ended by March.^[91] In the desert, there followed a temporary lull in combat which Germany used to prepare for their upcoming offensives.^[92][93]

The tide turns

American aircraft attacking a Japanese cruiser at the Battle of Midway.

In early May, Japan initiated operations to capture Port Moresby via amphibious assault and thus sever the line of communications between the United States and Australia. The Allies, however, intercepted and turned back Japanese naval forces, preventing the invasion.^[94] Japan's next plan, motivated by the earlier bombing on Tokyo, was to seize Midway Atoll lure American carriers into battle to be eliminated; as a diversion, Japan would also send forces to occupy the Aleutian Islands.^[95] In early June, Japan put their operations into action but the Americans, having broken Japanese naval codes in late May, were fully aware of the plans and force dispositions and used this knowledge to achieve a decisive victory over the Imperial Japanese Navy.^[96] With their capacity for aggressive action greatly diminished as a result of the Midway battle, Japan chose to focus on a belated attempt to capture Port Moresby by an overland campaign in the Territory of Papua.^[97] The Americans planned a counterattack against Japanese positions in the southern Solomon Islands, primarily Guadalcanal, as a first step towards capturing Rabaul, the main Japanese base in Southeast Asia.^[98] Both plans started in July, but by mid-September, the battle for Guadalcanal took priority for the Japanese, and troops in New Guinea were ordered to withdraw from the Port Moresby area to the northern part of the island.^[99] Guadalcanal soon became a focal point for both sides with heavy commitments of troops and ships in a battle of attrition. By the start of 1943, the Japanese were defeated on the island and withdrew their troops.^[100]

In Burma, Commonwealth forces mounted two operations. The first, an offensive into the Arakan region in late 1942 went disastrously, forcing a retreat back to India by May of 1943.^[101] The second was the insertion of irregular forces behind Japanese front-lines in February which, by the end of April, had achieved dubious results.^[102]

Soviet soldiers in the Battle of Stalingrad.

On Germany's eastern front, the Axis defeated Soviet offensives in the Kerch Peninsula and at Kharkov^[103] and then launched their main summer offensive against southern Russia in June, 1942, to seize the oil fields of the Caucasus. The Soviets decided to make their stand at Stalingrad which was in the path of the advancing German armies and by mid-November the Germans had nearly taken Stalingrad in bitter street fighting when the Soviets began their second winter counter-offensive, starting with an encirclement of German forces at Stalingrad^[104] and an assault on the Rzhev salient near Moscow, though the latter failed disastrously.^[105] By early February, the German Army had taken tremendous losses; their troops at Stalingrad had been forced to surrender and the front-line had been pushed back beyond its position prior to their summer offensive. In mid-February, after the Soviet push had tapered off, the Germans launched another attack on Kharkov, creating a salient in their front-line around the Russian city of Kursk.^[106]

In the west, concerns the Japanese might utilize bases in Vichy-held Madagascar caused the British to invade the island in early May, 1942.^[107] This success was off set soon after by an Axis offensive in Libya which pushed the Allies back into Egypt until Axis forces were stopped at El Alamein.^[108] On the Continent, raids of Allied commandos on strategic targets, culminating in the disastrous Dieppe Raid,^[109] demonstrated the Western allies' inability to launch an invasion of continental Europe without much better preparation, equipment, and operational security.^[110] In August, the Allies succeeded in repelling a second attack against El Alamein and, at a high cost, managed to get desperately needed supplies to the besieged Malta.^[111] A few months later the Allies commenced an attack of their own in Egypt, dislodging the Axis forces and beginning a drive west across Libya.^[112] This was followed up shortly after by an Anglo-American invasion of French North Africa, which resulted in the region joining the Allies.^[113] Hitler responded to the defection by ordering the occupation of Vichy France,^[113] though the Vichy Admiralty managed to scuttle their fleet to prevent its capture by German forces.^[114] The now pincered Axis forces in Africa withdrew into Tunisia, which was conquered by the Allies by May 1943.^[115]

Allies gain momentum

British troops firing a mortar during the Battle of Imphal.

In mainland Asia, the Japanese launched two major offensives. The first, started in March, 1944, was against British positions in Assam, India^[116] and soon led to Japanese forces besieging Commonwealth positions at Imphal and Kohima;^[117] by May however, other Japanese forces were being besieged in Myitkyina by Chinese forces which had invaded Northern Burma in late 1943.^[118] The second was in China, with the goal of destroying China's main fighting forces, securing railways between Japanese-held territory, and capturing Allied airfields.^[119] By June the Japanese had conquered the province of Henan and begun a renewed attack against Changsha in the Hunan province.^[120]

Following the Guadalcanal Campaign, the Allies initiated several operations against Japan in the Pacific. In May, 1943, American forces were sent to eliminate Japanese forces from the Aleutians,^[121] and soon after began major operations to isolate Rabaul by capturing surrounding islands, and to breach the Japanese Central Pacific perimeter at the Gilbert and Marshall Islands.^[122] By the end of March, 1944, the Allies had completed both of these objectives, and additionally neutralized another major Japanese base in the Caroline Islands. In April, the Allies then launched an operation to retake Western New Guinea.^[123]

In the Mediterranean, Allied forces launched an invasion of Sicily in early July, 1943. The attack on Italian soil, compounded with previous failures, resulted in the ousting and arrest of Mussolini later that month.^[124] The Allies soon followed up with an invasion of the Italian mainland in early September, following an Italian armistice with the Allies.^[125] When this armistice was made public on September 8th, Germany responded by disarming Italian forces, seizing military control of Italian areas,^[126] and setting up a series of defensive lines.^[127] On September 12th, German special forces further rescued Mussolini who then soon established a new client state in German occupied Italy.^[128] The Allies fought through several lines until reaching the main German defensive line in mid-November.^[129] In January 1944, the Allies launched a series of attacks against the line at Monte Cassino and attempted to outflank it with landings at Anzio. By late May both of these offensives had succeeded and, at the expense of allowing several German divisions to retreat, on June 4th Rome was captured.^[130]

A Soviet tank during the Battle of Kursk.

German operations in the Atlantic also suffered. By May 1943, German submarine losses were so high that the naval campaign was temporarily called to a halt as Allied counter-measures became increasingly effective.^[131]

In the Soviet Union, the Germans spent the spring and early summer of 1943 making preparations for a large offensive in the region of Kursk; the Soviets anticipated such an action though and spent their time fortifying the area.^[132] On July 4th, the Germans launched their attack, though only about a week later Hitler cancelled the operation.^[133] The Soviets were then able to mount a massive counter-offensive and, by June 1944, had largely expelled Axis forces from the Soviet Union and made incursions into Romania.^[134]

In November, 1943, Franklin Roosevelt and Winston Churchill met with Chiang Kai-shek in Cairo and then with Joseph Stalin in Tehran. At the former conference, the post-war return of Japanese territory was determined and in the latter, it was agreed that the Western Allies would invade Europe in 1944 and that the Soviet Union would declare war on Japan within three months of Germany's defeat.

Allies close in

Allied Invasion of Normandy.

After the Soviet relief of the siege of Leningrad in February 1944, the Soviet counter offensive was halted at the Estonian border for 8 months by the German Armed Forces, aided by a large number of Estonian conscripts and volunteers intent on the re-establishment of Estonian independence.^[135][136]

On 6 June 1944 (known as D-Day), the Western Allies invaded northern France and, after reassigning several Allied divisions from Italy, southern France;^[137] by 25 August, Paris was liberated.^[138] During the latter part of the year, the Western Allies continued to push back German forces in western Europe, and in Italy ran into the last major defensive line.

On June 22, the Soviets launched a strategic offensive in Belarus (known as "Operation Bagration") that resulted in the almost complete destruction of the German Army Group Centre.^[139] Soon after that, another Soviet major strategic offensive forced the German troops from Ukraine and Eastern Poland. Major assaults against Finland and Romania resulted in great successes, with Bulgaria, Romania and Finland signing armistices with the Soviet Union,^[140] and prompted Polish resistance forces to initiate several uprisings in Poland, though the largest of these, in Warsaw, was conducted without Soviet assistance and put down by German forces.^[141]. On October, the Soviets launched a massive assault against Germany occupied Hungary that lasted until the fall of Budapest on February 1945.^[142]

By the start of July, Commonwealth forces in Southeast Asia had repelled the Japanese sieges in Assam, pushing the Japanese back to the Chindwin River^[143] while the Chinese captured Myitkyina. In China, the Japanese were having greater successes, having finally captured Changsha in mid-June and the city of Hengyang by early August.^[144] Soon after, they further invaded the province of Guangxi, winning major engagements against Chinese forces at Guilin and Liuzhou by the end of November^[145] and successfully linking up their forces in China and Indochina by the middle of December.^[146]

In the Pacific, American forces continued to press back the Japanese perimeter. In the middle of June, 1944, they began their offensive against the Mariana and Palau islands, scoring a decisive victory against Japanese forces in the Philippine Sea within a few days. In late October, American forces invaded the Filipino island of Leyte; soon after, Allied naval forces scored another large victory against the Japanese in the Leyte Gulf.^[147]

Axis collapse, Allied victory

American and Soviet troops meet east of the Elbe River.

On December 16, 1944 German forces counter-attacked in the Ardennes against the Western Allies. It took six weeks for the Allies to repulse the attack. The Soviets attacked through Hungary, while the Germans abandoned Greece, Albania and were driven out of southern Yugoslavia by partisans.^[148] In Italy, the Western Allies remained stalemated at the German defensive line. In mid-January 1945, the Soviets attacked in Poland, pushing from the Vistula to the Oder river in Germany, and overran East Prussia.^[149]

On February 4, U.S., British, and Soviet leaders met in Yalta. They agreed on the occupation of post-war Germany,^[150] and when the Soviet Union would join the war against Japan.^[151]

In February, Western Allied forces entered Germany and closed to the Rhine river, while the Soviets invaded Pomerania and Silesia. In March, the Western Allies crossed the Rhine north and south of the Ruhr, encircling a large number of German troops, while the Soviets advanced to Vienna. In early April the Western Allies finally pushed forward in Italy and swept across western Germany, while in late April Soviet forces stormed Berlin; the two forces linked up on Elbe river on April 25.

Several changes in leadership occurred during this period. On April 12, U.S. President Roosevelt died; he was succeeded by Harry Truman. Mussolini was killed by Italian partisans on April 28th^[152] and two days later Hitler committed suicide, succeeded by Grand Admiral Karl Dönitz.^[153]

German forces surrendered in Italy on April 29th and in Western Europe on May 7.^[154] However, fighting continued on the Eastern Front until the Germans surrendered specifically to the Soviets on May 8. In Prague, resistance of remnants of German Army continued until May 11.

Nuclear explosion at Hiroshima.

In the Pacific theater, American forces advanced in the Philippines, clearing Leyte by the end of 1944. They landed on Luzon in January 1945 and Mindanao in March.^[155] British and Chinese forces defeated the Japanese in northern Burma from October to March, then the British pushed on to Rangoon by May 3.^[156] American forces also moved toward Japan, taking Iwo Jima by March, and Okinawa by June.^[157] American bombers destroyed Japanese cities, and American submarines cut off Japanese imports.^[158]

On July 11, the Allied leaders met in Potsdam, Germany. They confirmed earlier agreements about Germany,^[159] and reiterated the demand for unconditional surrender by Japan, specifically stating that "the alternative for Japan is prompt and utter destruction".^[160] During this conference the United Kingdom held its general election and Clement Attlee replaced Churchill as Prime Minister.

When Japan continued to reject the Potsdam terms, the United States then dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in early August. Between the two bombs, the Soviets invaded Japanese-held Manchuria, as agreed at Yalta. On August 15, 1945 Japan surrendered, ending the war.^[154]

Aftermath

Main article: Aftermath of World War II

Prime Minister Winston Churchill waves to crowds in London on Victory in Europe Day.

In an effort to maintain international peace,^[161] the Allies formed the United Nations, which officially came into existence on 24 October, 1945.^[162]

Regardless of this though, the alliance between the Western Allies and the Soviet Union had begun to deteriorate even before the war was over,^[163] and the two powers each quickly established their own spheres of influence.^[164] In Europe, the continent was essentially divided between Western and Soviet spheres by the so-called Iron Curtain which ran through and partitioned Allied occupied Germany and occupied Austria. In Asia, the United States occupied Japan and administrated Japan's former islands in the Western Pacific while the Soviets annexed Sakhalin and the Kuril Islands; the former Japanese governed Korea was divided and occupied between the two powers. Mounting tensions between the United States and the Soviet Union soon evolved into the formation of the American-led NATO and the Soviet-led Warsaw Pact military alliances and the start of the Cold War between them.^[165]

In many parts of the world, conflict picked up again within a short time of World War II ending. In China, nationalist and communist forces quickly resumed their civil war. Communist forces were eventually victorious and established the People's Republic of China on the mainland while nationalist forces ended up retreating to the reclaimed island of Taiwan. In Greece, civil war broke out between Anglo-American supported royalist forces and communist forces, with the royalist forces victorious. Soon after these conflicts ended, war broke out in Korea between South Korea, which was backed by the western powers, and North Korea, which was backed by the Soviet Union and China; the war resulted in essentially a stalemate and ceasefire.

Following the end of the war, a rapid period of decolonization also took place within the holdings of the various European colonial powers. These primarily occurred due to shifts in ideology, the economic exhaustion from the war and increased demand by indigenous people for self-determination. For the most part, these transitions happened relatively peacefully, though notable exceptions occurred in countries such as Indochina, Madagascar, Indonesia and Algeria.^[166] In many regions, divisions, usually for ethnic or religious reasons, occurred following European withdrawal; this was seen prominently in the Mandate of Palestine, leading to the creation of Israel and Palestine, and in India, resulting in the creation of the Dominion of India and the Dominion of Pakistan.

Economic recovery following the war was varied in differing parts of the world, though in general it was quite positive. In Europe, West Germany recovered quickly and doubled production from its pre-war levels by the 1950s.^[167] Italy came out of the war in poor economic condition,^[168] but by 1950s, the Italian economy was marked by stability and high growth.^[169] The United Kingdom was in a state of economic ruin after the war,^[170] and continued to experience relative economic decline for decades to follow.^[171] France rebounded quite quickly, and enjoyed rapid economic growth and modernization.^[172] The Soviet Union also experienced a rapid increase in production in the immediate post-war era.^[173] In Asia, Japan experienced incredibly rapid economic growth, and led to Japan becoming one of the most powerful economies in the world by the 1980s.^[174] China, following the conclusion of its civil war, was essentially a bankrupt nation.^[175] By 1953 economic restoration seemed fairly successful as production had resumed pre-war levels.^[176] This growth rate mostly persisted, though it was briefly interrupted by the disastrous Great Leap Forward economic experiment. At the end of the war, the United States produced roughly half of the worlds industrial output; by the 1970s though, this dominance had lessened significantly.^[177]

Impact of the war

Casualties and war crimes

Main articles: World War II casualties and War crimes during World War II

Estimates for the total casualties of the war vary, but most suggest that some 60 million people died in the war, including about 20 million soldiers and 40 million civilians.^{[178][179][180]} Many civilians died because of disease, starvation, massacres, genocide. The Soviet Union lost around 27 million people during the war, about half of all World War II casualties.^[181] Of the total deaths in World War II, approximately 85 percent were on the Allied side (mostly Soviet and Chinese) and 15 percent on the Axis side. One estimate is that 12 million civilians died in Nazi concentration camps,^[182] 1.5 million by bombs, 7 million in Europe from other causes, and 7.5 million in China from other causes.^[183] Figures on the amount of total casualties vary to a wide extent because the majority of deaths were not documented.

Many of these deaths were a result of genocidal actions committed in Axis-occupied territories and other war crimes committed by German as well as Japanese forces. The most notorious of German atrocities was The Holocaust, the systematic genocide of Jews in territories controlled by Germany and its allies. The Nazis also targeted other groups, including the Roma (targeting in the Porajmos), Slavs, and gay men, exterminating an estimated five million additional people.^[184] For Japan, the most well-known atrocity is the Nanking Massacre, in which several hundred thousand Chinese civilians were raped and murdered.^[185] Japanese military murdered from nearly 3 million to over 10 million civilians, mostly Chinese.^[186] According to Mitsuyoshi Himeta, at least 2.7 million died during the Sankō Sakusen implemented in Heipei and Shantung by General Yasuji Okamura.

Limited Axis usage of biological and chemical weapons is also known. The Italians used mustard gas during their conquest of Abyssinia,^[187] while the Japanese Imperial Army used a variety of such weapons during their invasion and occupation of China (see Unit 731)^[188] and in early conflicts against the Soviets.^[189] Both the Germans and Japanese tested such weapons against civilians^[190] and, in some cases, on prisoners.^[191]

While many of the Axis's acts were brought to trial in the world's first international tribunals,^[192] incidents caused by the Allies were not. Examples of such actions include population transfer in the Soviet Union, Japanese American internment in the United States, the Soviet massacre of Polish citizens and the controversial mass-bombing of civilian areas in enemy territory, most notably at Dresden.^[193]

Large numbers of deaths can also be attributed, if even partially, indirectly to the war, such as the Bengal famine of 1943.

Concentration camps and slave work

The Nazis were responsible for the killing of approximately six million Jews (overwhelmingly Ashkenazi) as well as two million ethnic Poles and four million others who were deemed "unworthy of life" (including the disabled and mentally ill, Soviet POWs, homosexuals, Freemasons, Jehovah's Witnesses, and the Roma) as part of a program of deliberate extermination planned and executed by the Nazi Germany. About 12 million, most of whom were Eastern Europeans, were employed in the German war economy as forced labor in Germany during World War II.^[194]

Victims of the Holocaust.

In addition to the Nazi concentration camps, the Soviet Gulag, or labor camps, led to the death of citizens of occupied countries such as Poland, Lithuania, Latvia, and Estonia, as well as German prisoners of war (POW) and even Soviet citizens themselves who had been or were thought to be supporters of the Nazis.^[195] Sixty percent of Soviet POWs died during the war.^[196] Richard Overy gives the number of 5.7 million Soviet POWs. Of those, 57% died or were killed, a total of 3.6 million.^[197] The survivors on their return to the USSR were treated as traitors (see Order No. 270).^[198]