World War II, or the Second World War, (often abbreviated WWII or WW2) was a global military conflict which involved a majority of the world's nations, including all of the great powers, organised into two opposing military alliances: the Allies and the Axis. The war involved the mobilisation 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.
The Start of the War
The start of the war is generally held to be in September 1939 with the German invasion of Poland and subsequent declarations of war on Germany by the United Kingdom, France and the British Dominions. Many belligerents entered the war before or after this date, during a period which spanned from 1937 to 1941, as a result of other events. Amongst these main events are the Marco Polo Bridge Incident, the start of Operation Barbarossa, and the attack on Pearl Harbor and British and Dutch colonies in South East Asia.
The Soviet Union and the United States emerged from the war 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 decolonisation movements in Asia and Africa, while Western Europe itself began moving toward integration.
In Europe, the origins of the war are closely tied to the rise of fascism, especially in Nazi Germany. A discussion of how the Nazis came to power is a requisite in this context.
Origins of the Second World War
The origins of the Second World War are generally viewed as being traced back to the First World War (1914-1918). In that war Germany under the ultra-nationalistic Kaiser Wilhelm II along with its allies, had been defeated by a combination of the United Kingdom, United States, France, Russia and others. The war was directly blamed by the victors on the miltant nationalism of the Kaiser's Germany; it was Germany that effectively started the war with an attack on France through Belgium. France, which had suffered a previous defeat at the hands of Prussia (a state that merged one year later with others to form Germany) in the Franco-Prussian War in 1870, demanded revenge for its financial devastation during the First World War (and its humiliation in the earlier war) ensured that the various peace treaties, specifically the Treaty of Versailles imposed tough financial reparations and restrictions on Germany.
The Weimar Republic
A new democratic German republic, known as the Weimar Republic, came into being. After some success it was hit by hyperinflation and other serious economic problems. Right wing nationalist elements under a variety of movements, but most notably the Nazi Party of Adolf Hitler, sought to blame Germany's "humiliating" status on the harshness of the post-war settlement, on the weakness of democratic government, and on the Jews, whom it claimed possessed a financial stranglehold on Germany. Hitler was appointed Reichskanzler (Chancellor) on January 30, 1933, by the aged President von Hindenburg. Hitler's government exercised much of its power through the special emergency powers possessed by the President under the constitution.
These powers enabled a government with the President's powers to effectively bypass the Reichstag (federal parliament). Under a further disastrous clause in the Weimar constitution when the President died, his office was temporarily assumed by the Chancellor. As a result, when Hindenburg died, the immense powers of the presidency fell into the hands of Adolf Hitler. Through the possession of those powers and an Enabling Act that allowed the nazi government to bypass and ignore the constitution, Hitler ensured his possession of the presidential powers became permanent and so gained dictatorial control over Germany.
The Italian economy also fell into a deep slump following World War I. Anarchists were endemic, Communist and other Socialist agitators abounded among the trade unions, and many were gravely worried that a Bolshevik-style Communist revolution was imminent.
After a number of liberal governments failed to rein in these threats, Italy's King Victor Emmanuel III invited right-wing politician Benito Mussolini and his Fascist Party to form a government in 1922, following their largely symbolic Marca su Roma (March on Rome). The Fascists maintained an armed paramilitary wing, which they employed to fight Anarchists, Communists, and Socialists.
Within a few years, Mussolini had consolidated dictatorial power, and Italy became a police state. On January 7, 1935, he and French Foreign Minister Pierre Laval signed the Italo-French agreements.
Meanwhile in Germany, once political consolidation (Gleichschaltung) was in place, the Nazis turned their attention to foreign policy with several increasingly daring acts.
On March 16, 1935, the Versailles Treaty was violated as Hitler ordered Germany to re-arm. Germany also reintroduced military conscription (the treaty stated that the German Army should not exceed 100,000 men).
These steps produced nothing more than official protests from Britain and France, for they were more serious about enforcing the economic provisions of the treaty than its military restrictions. Many Brits felt the restrictions placed on Germany in Versailles had been too harsh, and they believed that Hitler's aim was simply to undo the extremes of the treaty, not to go beyond that. Faced with no opposition, Hitler moved troops into the Rhineland on March 7, 1936. Under the Versailles treaty, the Rhineland should have been demilitarized, for France wanted it for a buffer between herself and Germany. But, as before, Hitler's defiance was met with inaction.
The first German conquest was Austria. After Italy had joined the Anti-Comintern Pact, thereby removing the main obstacle of a Anschluss of Austria, Germany announced the annexation on March 12, 1938, making it a German province: "Gau Ostmark."
With Austria secured, Hitler turned his attention to Czechoslovakia. His first order of business was to seize the Sudetenland, a mountainous area in northeast part of the country. With Austria in German hands, the tiny state was nearly surrounded. Following lengthy negotiations, and blatant war threats from Hitler, British Prime Minister Neville Chamberlain went out of his way with French leaders to appease Hitler, even though the United Kingdom had earlier guaranteed the security of Czechoslovakia. However, the Munich Agreement of September 30, 1938, then allowed German troops to occupy the Sudetenland.
Czech representatives were not allowed at the conference; their government strongly opposed giving up the Sudetenland but they were powerless in the face of German military might and British and French unwillingness to support them. A few months after that, in March 1939, the remaining Czech lands passed into German hands as well. March 14 Slovakia declared her independence, recognized by France, Britain and other important powers. The Slovak state tried to avoid nazification, but was finally occupied by Nazi-Germany in September 1944.
Italy, facing opposition to its wars in Abyssinia (Ethiopia) from the League of Nations, forged an alliance with Nazi Germany, which had withdrawn from the League in 1933. In May of 1939, Italy and Germany thus formed the Pact of Steel, which deepened their alliance and established a Rome-Berlin "Axis."
Outbreak of War in Europe
Germany and the Soviet Union, the two most powerful dictatorships in Europe, were sworn enemies, but political realities allowed them to sign a non-aggression pact (Molotov-Ribbentrop Pact) including a secret clause partitioning Poland, the Baltic Republics and Finland between the two.
Full-scale war in Europe began on September 1, 1939, when Germany invaded Poland, to which both Britain and France had pledged guarantees (see: Polish September Campaign 1939). On September 17, the Soviet Union invaded Poland from the east. Poland fell quickly, with her last large operational units surrendering October 5. However, Polish troops continued fighting for the Allied until the end of the war. Dresden after Allied bombing
Allied bombing of the German city of Dresden later in the war proved controversial. 85% of the baroque city was destroyed. full size view of the picture view of the effects from the air.
Despite the quck campaign in the east, along the Franco-German frontier the war settled into a quiet period. This relatively non-confrontational period between the major powers lasted until May 10, 1940, and was known as the Phony War. Scandinavian Campaigns
Several other countries, however, were drawn into the conflict at this time. By September 28, 1939, the three Baltic Republics felt they had no choice but to permit Soviet bases and troops on their territory.
Finland was invaded by the Soviets on November 30. This began the Winter War. After over three months of hard fighting, and heavy losses, the Soviet Union gave up the attempted invasion. In the Moscow Peace Treaty, March 12, Finland ceded 10% of her territory. The Finns were embittered over having lost more land in the peace than on the battle fields, and over the seemingly little use of the whole world's sympathy.
On April 9 Germany commenced Weserübung to seize Denmark and Norway, ostensibly as a defensive maneuver against a planned (and openly discussed) Franco-British occupation of those countries aimed at controling export of Swedish iron ore and the Northern Atlantic. After the failed British campaign in Norway Finland and Sweden were physically cut off from the West. As a consequence, Germany put pressure on neutral Sweden to permit transition of military goods and soldiers on leave. Germany's presense proximate to northernmost Finland, and its Nickel mines, were perceived as an improvement of the strategical situation by the Finns. War Comes to the West
On March 18, 1940, Hitler and Mussolini had agreed to make the Axis Powers' Pact of Steel an alliance against France and the United Kingdom.
On May 10 the Phony War ended with a sweeping German invasion of Belgium, the Netherlands and Luxembourg, that bypassed French fortifications along the Maginot Line.
After overrunning these countries Germany turned against France, entering the country through the Ardennes on May 13 - the French had made the fatal mistake of leaving this area almost totally undefended, believing its terrain to be impassible for tanks. Most Allied forces were in Flanders, anticipating a re-run of the World War I Schlieffen Plan, and were cut off from the French heartland. As a result of this, and also the superior German communications, the Battle of France was shorter than virtually all prewar Allied thought could have conceived. It lasted six weeks, after which France surrendered.
In order to further the humiliation of the French people, Hitler arranged for the surrender document to be signed in the same railway coach where the German surrender had been signed in 1918. The fall of France left Britain and its Empire to stand alone. Fortunately for Britain, much of its army escaped capture from the northern French port of Dunkirk. The exploits of the "little ships" at Dunkirk were exploited for propaganda purposes to turn the disasterous defeat into something approaching a victory in the minds of the British people. In total, 330,000 troops were pulled off the beaches, of which 230,000 were British.
The Germans massed their air force in northen France to prepare the way for a possible invasion, codenamed Operation Seelöwe. The operations of the Luftwaffe against RAF Fighter Command became know as the Battle of Britain. It is widely held that the invasion could never realistically have been mounted successfully. Even had the Luftwaffe driven the RAF from the skies of southern England, which was the object of the Battle of Britain for the Germans, there would still have been the remains of Fighter Command in the Midlands and northern England, Bomber Command, and Coastal Command, along with the firepower of the Home Fleet for the Germans to contend with. It is likely that had the invasion been attempted that German troops would have been landed and cut off by British sea- and airpower, to be destroyed virtually at leisure. After the failure to destroy Fighter Command, the Luftwaffe switched to bombing major British cities. That bombing campaign is commonly know as the Blitz.
During the Blitz, all of Britain's major industrial cites were heavily bombed. London suffered particularly, being bombed each night for several months. Other targets included Birmingham and Coventry, and strategically important cities, such as the naval base at Plymouth and the port of Kingston upon Hull.
With no land forces in direct conflict in Europe, the war in the air attracted worldwide attention even as sea units fought the Battle of the Atlantic and a number of British commando raids hit targets in occupied Europe. More critical was the war in the air.
Prewar doctrine had held that waves of bombers hitting enemy cities would cause mass panic and the rapid collapse of the enemy. As a result, the Royal Air Force had built up a comparatively large strategic bomber force. By way of contrast, German air force doctrine was almost totally dedicated to supporting the army. Therefore, German bombers were smaller than their British equivalents, and the Germans never developed a four engined heavy bomber equivalent to the Lancaster, B-17 or B-24.
The main concentration of German raids on British cities was from autumn 1940 until spring 1941. After that a large proportion of the strength of the Luftwaffe was diverted to the war against the Soviet Union. German raids continued on a smaller scale for the rest of the war, and later the V-1 cruise missile and V-2 ballistic missile were both used against Britain. However, the balance of bomb tonnage being dropped shifted greatly in favour of the RAF as Bomber Command gained in strength. By 1942, Bomber Command could put 1,000 bombers over one German city. However, it should be noted that this was a special effort using all available aircraft and training units as well. It was 1943 before 1,000 bomber raids became possible without a special effort. From 1942 onwards, the efforts of Bomber Command were supplemented by the Eighth Air Force of the United States Army Air Force. Bomber Command raided by night and the US forces by day. During 1943, a raid on Hamburg produced one of the most devastating fires in history. A firestorm was created in the city, and 40,000 people were killed. Only the raid on Dresden in 1945, the firebombing of Tokyo and the atomic bombs killed more people through a single attack. In addition to the direct damage caused by these attacks, large amounts of resources were diverted to air defense. The Balkans
On October 28 1940, Italy invaded Greece but was unable to match the German's success in France. Not only did the Italians fail to conquer Greece, but the Greeks successfully counterattacked into Albania. This prompted German intervention, which also involved the invasion of Yugoslavia, where a pro-German coup had been defeated a few days earlier. British forces were dispatched from Egypt to Greece, but were comprehensively beaten. After the mainland was conquered, the Germans invaded Crete. Instead of an amphibious assault as expected, the Germans mounted a large airborne invasion. It suceeded, but the paratroops of the German army were so badly mauled in the process that an airborne operation was never again attempted by Germany during the war.
Once the Balkans was secure, the largest land operation in history was launched, when Germany attacked the Soviet Union. The Eastern Front
On June 22, 1941, the Germans launched a surprise invasion, code-named Operation Barbarossa, against their erstwhile Soviet allies. The early weeks of the invasion were devastating for the Soviet Army. Enormous numbers of Soviet troops were encircled in pockets and fell into German hands. However, it wasn't only German troops that went into the Soviet Union. Italian, Hungarian and Romanian troops were also involved in the campaign.
Out of all the adversaries of the Allies, the situation of Finland was unique. Finland initially declared neutrality, however with German and Soviet troops on her soil, and well prepared for co-belligerence with Germany when the Soviet Union attacked on June 25. The following conflict from 1941-1944 is referred to as the Continuation War, i.e. the continuation of the Winter War.
Operation Barbarossa suffered from several fundamental flaws. The most serious of these was the logistical situation of the attack. Ultimately it is logistics that determine what a military can do. The sheer vastness of the distances in the Soviet Union meant that the Germans could only advance so far before outrunning their supply chains. By the time the German attack froze to a halt before Moscow on December 5, 1941, it literally could not go any further. There simply were not enough supplies reaching the front to conduct proper defensive operations, let alone a proper offense. The timetable that Barbarossa was planned to assumed that the Soviets would collapse before the Russian winter hit. The failure of that to happen also fatally affected German plans.
During their long retreat, the Soviets employed a scorched earth policy. They burnt crops and destroyed utilities as they withdrew before the Germans. That helped to contribute to the logisical problems that the Germans experienced. The extension of the campaign beyond the length that the Germans expected meant that the German Army suffered hundreds of thousands of casualties in the bitter cold of the Russian winter, and from the counterattacks of Soviet units.
Even with their advance having ground to a halt due to a lack of supplies and the onset of winter, the Germans had conquered a vast amount of territory. Dislodging them cost the Soviet Union dearly and took until late 1944.
Once the Germans had conquered so much of the Soviet Union, one of the great tragedies of the war began, the siege of Leningrad: Leningrad (now Saint Petersburg) was reached fairly quickly, from the North by Finnish forces, and from the South by the German Wehrmacht. Finland's C-in-C Mannerheim had halted at the River Svir and refrained from attacking the city.
Hitler had ordered that the city of Leningrad must "vanish from the surface of the earth", with its entire population exterminated. Rather than storming the city, the Wehrmacht was ordered to blockade Leningrad so as to starve the city to death, while attacking it with bombers and artillery. About one million civilians died in the Leningrad siege - 800,000 by starvation. It lasted 900 days, and at its height the only way into the city was across Lake Ladoga, between the German and Finnish lines.
After enduring the winter of 1941/42, the German army prepared for further offensive operations. Instead of trying to reach Moscow, the objective was changed to Stalingrad (now Volgograd) near the Caucasus region of Russia. Stalingrad was captured, however the course of the campaign took a turn for the worse due to disparate objectives, and a lack of focus.
Indecision by Hitler, dissent among the higher ranked German officers, and extended supply lines combined in a prolonged battle in the streets of Stalingrad. In an attempt to capture the city, almost all Germans in the area were funneled into the city leaving only weak Romanian and Hungarian forces on the flanks of the salient. After a Soviet counteroffensive destroyed these forces, the German 6th Army was cut off in the city itself, along with part of the 4th Panzer Army. Starved of food, fuel and ammunition, the pocket was gradually reduced, with the last portion surrendering in early 1943. In a cynical attempt to prevent the surrender, Hitler promoted the commander of 6th Army to Field Marshal, because no German of that rank had ever surrendered. Heavy losses affected both sides in the Battle of Stalingrad, one of the bloodiest battles in history. An estimated 2 million people perished in this battle, including 500,000 civilians.
After Stalingrad, the initiative had passed from the Germans but had not yet been seized by the Soviets. A desparate counterattack in the spring of 1943 by the forces of von Manstein halted the Soviet advance for the moment, and set up the largest tank battle in history, Kursk. Kursk was the last major offensive by the Germany Army on the eastern front. The Soviets had intelligence of what was to come and prepared massive defences in huge depth in the Kursk salient. They stopped the German armoured thrusts after a maximum penetration of 17 miles. After Kursk the Red Army never ceased being on the offensive until Berlin was captured in May 1945.
The Soviets bore the brunt of World War II; the second front in Europe did not begin until D-Day, apart from the invasion of Italy. More Soviet citizens died during World War II than those of all other countries combined. Approximately 27 million Soviets, among them more than 13 million civilians, were killed in the German invasion of the Soviet Union. Civilians were rounded up and burned or shot in many cities conquered by the Nazis. Since the Nazis considered Slavs to be "subhuman", this was ethnically targeted mass murder.
It would be wrong however to say the Soviets fought alone. Supply convoys sailed to Soviet ports at great risk. Allied activities may have tied up only a few divisions in actual fighting, but many more were forced to guard lonely coasts against raids that never came or to man antiaircraft guns throughout Europe. It should also be mentioned that the Soviets took virtually no part in the great naval campaigns of the war, had a very limited effect on the strategic bombing offensive, and contributed very little to the defeat of Japan.
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. Thus began a seesaw campaign that culminated in the two Battles of El Alamein. The first battle took place in summer 1942. The Germans had advanced to El Alamein, the last defensible point before Alexandria and the Suez Canal. However, as in the Soviet Union, they had outrun their supplies, and a British defence stopped their thrusts.
The later of the two battles, in the late autumn saw British forces take the offensive. 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. Vichy French forces put up limited resistance before joining the Alied 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 Germans out of Africa and on May 13, 1943, the remnants of the Axis forces in North Africa surrendered. Not widely known is that the number of prisoners taken in this incident, 250,000 was as many as at Stalingrad. The Allies' Invasion of Italy
With the North African shore acting as a springboard, an Allied blow into what Churchill referred to as the 'soft underbelly' of Europe was inevitable.
A prelude of this attack was the capture of the offshore island of Sicily on 10 July, 1943. This took the wind out of the bombastic Mussolini. He was deposed on July 25, 1943, by the Fascist Grand Council.
He was arrested and placed under house arrest in an isolated mountain resort. His replacement, General Pietro Badoglio, negotiated an armistice with the Allies on September 8, 1943.
The Germans moved quickly into the confused situation, disarmed Italian formations and established strong defensive lines.
Allied troops landed in mainland Italy on September 9, 1943; the American at Salerno, the British at Taranto.
Mussolini was rescued by the Germans and installed as the head of a Nazi puppet state in northern Italy. He continued in this role until he was captured and lynched by mobs on April 28, 1945, as the Allied forces closed in on Milan.
The Germans had built a fortified zone in the mountains called the Gustav line. The Allied forces attacked both sides of the line, attacking Monte Cassino from the south and landing at Anzio in the north.
The Allies finally entered Rome on June 4, 1944, two days before the landings in Normandy. The Germans regrouped at the Gothic Line further north. After a landing in southern France in August to threaten the German flank, British forces started the attack on the line September 10. The offensive by Allied and some Italian forces continued until the Germans surrendered in Italy on April 29, two days after Mussolini's capture. The Allies' Invasion of France
Essentially simultaneously with the fall of Rome came the long-awaited invasion of France. Operation Neptune put troops ashore in Normandy on June 6 1944. A long grinding campaign two months long followed as American, British and Canadian forces were slowly built up in the bridgehead, and German forces slowly worn down. When the breakout finally did come it was spectacular, with American forces under Patton racing across France to the German border. The German forces that had been fighting in Normandy were trapped in a pocket around Falaise. General Charles de Gaulle
Leader of the Free French in opposition to Petáin's Vichy regime. Incessant bombing of Germany's infrastructure and cities caused tremendous casualties and disruption. Internally, Hitler survived a number of assassination attempts. The most serious was the July 20 Plot, in which Hitler was slightly injured.
Operation Neptune was complemented by an invasion of southern France in August codenamed Operation Dragoon - the combined operation was referred to as Operation Overlord. By September, three Allied Army Groups were in line against German formations in the west. There was optimism that the war in Europe might be over by the end of 1944.
An attempt was made to force the situation with Operation Market Garden. The Allies attempted to capture bridges with an airborne assault, to open the way into Germany and liberate the northern Netherlands. Unfortunately, heavier German forces than intelligence had predicted were present. The British 1st Airborne Division was almost completely destroyed.
The cold winter of 1944
The cold winter of 1944 combined with a poor situation for the Allies led to a stagnate situation on the western front. The Americans continued to grind away at the defenders in the Battle of Hurtgen Forest. As long as they stayed on the defense, the Allies were hard-pressed to advance rapidly.
That changed when the Germans mounted a major counteroffensive on Dec 16, 1944. The Ardennes offensive, also called the Battle of the Bulge, drove back and surrounded some American units. The Allied forces were eventually successful in driving back the Germans, in what turned out to be their last major advance of the war.
The final obstacle to the Allies was the River Rhine. It was crossed in April 1945, and the way lay open to the heart of Germany. The last German forces in the west were encircled in the Ruhr.
The End of the War in Europe
On April 25, 1945 United States and Russian troops linked-up at the Elbe River, cutting Germany in two.
Thousands of Holocaust victims arriving at the Nazi extermination camp at Birkenau in 1944
When all was lost, Hitler committed suicide in his bunker along with his lover, Eva Braun. The German Empire was partitioned by the Allies into an area of Soviet control, which became East Germany, and an area of joint British/French/American control, which became West Germany. The final surrender documents were signed by General Alfred Jodl on May 7, 1945. May 8 was declared V-E (Victory In Europe) Day.
Following the war, Allied soldiers discovered a number of concentration camps and other locations that had been used by the Nazis to imprison and exterminate an estimated 12 million people. The largest single group represented in this number were Jewish (roughly half the total according to the Nuremburg trials), but Gypsies, Slavs, Catholics, homosexuals and various minorities and disabled persons formed the remainder. The most well-known of these camps is the death camp Auschwitz in which about two million prisoners were killed. Although the Nazi genocide or "Holocaust" was largely unknown to the Allied soldiers fighting the war, it has become an inseparable part of the story of World War II.
The Pacific Theater
In the Pacific, war was not formally declared between the belligerents until after the Japanese attack on Pearl Harbor on December 7, 1941. (See: Greater East Asia War). However, there was active fighting dating back to the 1930s, the cause of which can be seen in the political fragmentation and weakness of China combined with a strong Japan with a militaristic and expansionist ideology.
In the 1920s, China fragmented into warlordism in which there was a weak central government, and Japan was able gain influence in China by imposing unequal treaties with what remained of the central government. This situation was unstable in that if China dissolved into total anarchy these agreements would be unenforceable while if China was able to strength, the strong China would be able to abrogate those agreements.
In 1927, Chiang Kai-Shek and the National Revolutionary Army of the Kuomintang led the Northern Expedition. Chiang was able to militarily defeat the warlords in southern and central China, and was in the process of securing the nominal allegiance of the warlords in northern China. Fearing that Zhang Xueliang (the warlord controlling Manchuria) was about to declare his allegiance for Chiang, the Japanese intervened and set up the puppet state of Manchukuo.
There is no evidence that Japan ever intended to directly administer China or that Japan's actions in China were part of a program of world domination. Rather, Japan's goals in China were strongly influenced by 19th century European colonialism and were to maintain a secure supply of natural resources and to have friendly and pliable governments in China that would not act against Japanese interests.
Although Japanese actions would not have seemed out of place among European colonial powers in the 19th century, by 1930, notions of Wilsonian self-determination meant that raw military force in support of colonialism was no longer seen as appropriate behavior by the international community. Japanese actions were therefore roundly criticized and led to Japan's withdrawal from the League of Nations. During the 1930s, China and Japan reached a stalemate with Chiang focusing his efforts at eliminating the Communists whom Chiang considered to be a more fundamental danger than the Japanese. The influence of Chinese nationalism on opinion both in the political elite and the general population rendered this strategy increasingly untenable.
Meanwhile in Japan, a policy of assassination by secret societies and the effects of the Great Depression had caused the civilian government to lose control of the military. In addition, the military high command had limited control over the field armies who acted on their own interest, often in contradiction to the overall national interest. There was also an upsurge in nationalism and anti-European feeling and the belief that Japanese policies in China could be justified by racial theories. One popular belief with similarities to the Identity movement was that Japan and not China was the true heir of classical Chinese civilization.
In 1937, Chiang was kidnapped by Zhang Xueliang in the Xian Incident. As condition of his release, Chiang promised to united with the Communists and fight the Japanese. In response to this, officers of the Kwangtung Army without knowledge of the high command in Tokyo decided to manufacture the Battle of Lugou Bridge, also known as the incident at the Marco Polo Bridge, by which they succeeded in their intention of provoking a conflict between the Republic of China and the Empire of Japan, the Sino-Japanese War).
In 1939 Japanese forces tried to push into the Soviet far east from Manchuria. They were soundly defeated by a mixed Soviet and Mongolian force led by Georgi Zhukov. This stopped Japanese expansion to the North and Japan and the Soviet Union kept un uneasy peace until 1945.
Japan's policies in the 1930s are remarkable for their disastrously self-defeating nature. Japan's grand strategy was based on the premise that it could not survive a war against the European powers without secure sources of natural resources, yet to secure those resources it decided to undertake the war that it knew it could not win in the first place. Moreover actions such as its brutality in China, and its practice of first setting up, and then undermining, puppet governments in China were clearly antithetical to Japan's overall goals, and yet it continued to persist in them anyway. Finally, this march to self-destruction is remarkable in that many individuals within the Japanese political and military elite realized these self-destructive consequences, but were unable to do anything about the situation. Also, there appears to have been no debate over policy alternatives which might have enabled Japan to further its goals in China.
Outbreak of war in the east
By 1941, Japan had occupied much of north and central China. However, Japan was faced with continued opposition from both the Kuomintang and the Communist Party of China. Although Japan was deeply mired in a quagmire, it did not undertake or even consider undertaking policies which would help it resolve the situation. Although it created several puppet governments, its policies of brutality toward the Chinese population, of not yielding any real power to the governments, and of support to several competing governments failed to make any of them a popular alternative to Chiang government. Japan was also unwilling to negotiate directly with Chiang, nor was it willing to attempt to create splits in united front against it, by offering concessions that would make it a more attractive alternative than Chiang's government. Instead, Japan's reaction to its situation was to turn to increasingly more brutal and depraved actions in the hope that sheer terror would break the will of the Chinese population.
This, however, only had the effect of turning world public opinion against it. In an effort to discourage Japan's war efforts in China, the United States, United Kingdom, and the government in exile of the Netherlands (still in control of the oil-rich Dutch East Indies) stopped trading oil and steel (both war staples) with Japan. Japan saw this as an act of aggression, as without these resources Japan's military machine would grind to a halt, and on December 7, 1941, Japanese forces invaded Siam, Malaya, and the Philippines, and attacked the American fleet at Pearl Harbor. Faced with this situation and with the belief that Although Japan knew that it could not win a sustained and prolonged war against the United States, it was the Japanese hope that, faced with this sudden and massive defeat, the United States would agree to a negotiated settlement that would allow Japan to have free reign in China. They were incorrect, and Japan was faced with a war it knew it could not win.
Four days later, Germany declared war on the United States, drawing America into a two-theater war. Until then, America had remained out of the conflict, though it was providing military aid to Britain and Soviet Union through the Lend-Lease program.
Allied forces in Asia, drained of men and materiel by the European conflict, were unable to provide much more than token resistance to the battle-hardened Japanese. Major units of the British fleet were sunk off Malaya on 10th December, and Hong Kong fell on the 25th. United States bases on Guam and Wake Island were lost at around the same time. January saw the invasions of Burma, the Solomons, the Dutch East Indies and New Guinea, and the capture of Manila, Kuala Lumpur and Rabaul. The pace of conquest was rapid: Bali and Timor fell in February 1942, Rangoon and Java in March, and Mandalay at the beginning of May. Meanwhile, Japanese aircraft had all but eliminated British and American air power in South-East Asia, made major raids on northern Australia, and driven the British fleet out of Ceylon.
Allied resistance, at first shambolic, gradually began to stiffen. The Doolittle Raid in April was a token but morale-boosting air attack on Japan, and although the US Navy was narrowly defeated in tactical terms at the Battle of the Coral Sea, it still managed to derail the Japanese plan to invade Port Moresby. The crucial Battle of Midway followed in June: the fortunes of war could easily have given either side the victory, but Japanese naval aviation suffered a devastating defeat from which it never recovered. Midway was the turning-point of the naval war in the Pacific theatre.
On land, the British/Indian retreat in Burma had slowed, Australian forces in New Guinea successfully defended Port Moresby along the Kokada Track and in August Japanese land forces suffered their first outright defeat of the war at the Battle of Milne Bay. At the same time, US and Japanese soldiers both attempted to occupy the island of Guadalcanal. Forces converged on Guadalcanal over the following six months in an escalating battle of attrition, with eventual victory going to the United States. From this time on the Japanese fought a defensive war.
The constant need to reinforce Guadalcanal weakened the Japanese effort in other theatres, leading to the recapture of Buna/Gona by Australian and US forces in early 1943, and preparing the way for both MacArthur's land-based thrust through New Guinea and Nimitz's island hopping campaign across the Pacific.
Hard-fought battles at Tarawa, Iwo Jima, Okinawa, and others resulted in horrific casualties on both sides, but finally produced a Japanese retreat. Faced with the loss of most of their experienced pilots, the Japanese resorted to kamikaze tactics in an attempt to slow the U.S. advance. On February 3, 1945, Japan's longtime enemy Russia agreed to enter the Pacific Theatre conflict against Japan and was soon making advances in Japanese-occupied Manchuria. Meanwhile, Tokyo and other Japanese cities suffered greatly from attacks by American bombers. Japan finally surrendered after the cities Hiroshima and Nagasaki, both industrial and civilian targets, were destroyed by nuclear weapons.
The final surrender was signed September 2, 1945, on the battleship Missouri. Following this period, General Douglas MacArthur established bases in Japan to oversee the postwar development of the country. This period in Japanese history is known as the occupation. President Harry Truman officially proclaimed an end of hostilities in on December 31, 1946.
Most likely learning from the example of 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 "Economic Recovery Program", better known as the Marshall Plan, called for the US Congress to allocate billions of dollars for the reconstruction of Europe.
The portion of Europe occupied or dominated by the Soviet Union did not participate in the plan. In the Paris Peace Treaty Soviet's enemies Hungary, Finland and Rumania were required to pay war reparations on $300,000,000 each (in 1938 year's value) to USSR and her satelites. Also Italy paid $360,000,000, shared chiefly between Greece, Yugoslavia and the Soviet Union.
As mentioned, the Soviets bore the heaviest casualties of World War II. This may explain much of Russia's behavior after the war. The Soviet Union continued to occupy and dominate Eastern Europe as a "buffer zone"against another invasion from the West. Russia had been invaded three times in the 150 years before the Cold War: during the Napoleonic Wars, World War I, and World War II, suffering tens of millions of causalities.
At the same time, the United States and the Soviet Union consolidated their military presence and links in Europe as preparation against possible aggression. In Churchill' words, an Iron Curtain had descended across Europe and a new phase of the conflict between the democaracies and Soviet Union, the Cold War began.
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 the military sphere, it seems World War II marked the coming of age of airpower, mostly at the expense of warships. While the penduleum continues to swing in this never-ending competition air powers are now a full partner in any military action.
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-trained militaries.
After the war, many high-ranking Nazis and Japanese leaders were prosecuted for war crimes, as well as the mass murder of the Holocaust. See Nuremberg trials.