O Level Revision : History - World War II: 1939-1945

World War II or the Second World War, was a global war that lasted from 1939 to 1945 which involved the vast majority of the world's countries—including all the great powers—forming two opposing military alliances: the Allies and the Axis powers.

Causes of World War II


Long term  causes


(a)  German rearmament (Failure of disarmament)


After the First World War:

-     German army was reduced to 100 000 men, was to have no tanks and heavy guns.

-     Germany  was  to  have  a  small  navy  with six battle-ships, thirty smaller vessels and surrender  the  rest  of  her  fleet to  the  allied forces.

-     Germany was not to have any military aircraft.

  • Germany showed its first defiance by destroying the vessels which were to be handed over to the Allies.
  • The Weimar Republic that was created by the Allied powers did not seriously adhere to the terms of the Versailles Treaty. However, the Weimar Republic was accepted as a member of the League of Nations in 1926.
  • When Hitler became Chancellor in January 1933, he started a programme of permanent rearmament.
  • The League of Nations condemned it and Germany withdrew from the League in October 1933.
  • By May 1935 he re-introduced conscription and increased the size of the army beyond the Treaty of Versailles limit. This was a serious breach of the Versailles Treaty.
  • At   the   Disarmament   Conference   of   1932-35 German wish of having an equal status was rejected.
  • Germany   wanted   to   have   prototype   weapons possessed by other powers.
  • France rejected the formula for relative strengths suggested by Britain and Italy.
  • In April 1935 an attempt was made by Britain, France and Italy to oppose the revival of German militarism but failed. The agreement, called the Stressa Front, was not effective.
  • In 1935 Britain decided to act alone by having the Anglo-German Naval Agreement which stated that the German naval fleet was to be 35% of that of Britain.
  • It appeared a friendly understanding but was in fact an acknowledgement of Germany’s rearmament after 1934.


(b)  Acts of aggression by Germany, Italy and Japan

  • Germany was encouraged by Italy and Japan who had expansionist ideas.
  • Germany saw the invasion of Ethiopia by Italy between October 1935 and May 1936. The League of Nations did nothing to stop the aggression.
  • Hitler did not condemn the invasion of Ethiopia like other powers in Europe.
  • Japan occupied Manchuria in 1931. The League of Nations did nothing.
  • Germany  entered   the   Rhineland,   ending   the demilitarisation status of the area and breaching the Versailles Treaty, directly challenging France and Britain.
  • This militarisation of the Rhineland earned Hitler prestige among Germans all over Europe. Italy did not condemn it because Germany and Italy had common ideologies.
  • Germany and Italy backed General Franco in the Spanish Civil War of July 1936, thus aggravating tension in Europe.
  • In October 1936 Germany and Italy signed the Rome-Berlin Axis marking the beginning of cooperation between the two states.
  • In November  1937  Germany  and  Japan  signed the Anti-Comintern Pact to oppose international communism. This brought the aggressors close together.
  • In  1937,  Germany,  Italy  and  Japan  signed  the Rome-Berlin-Tokyo Axis.
  • In May 1939 Germany and Italy signed the Pact of Steel. Italy agreed to give Germany military support whenever Germany needed it and vice- versa.
  • In 1939 Germany invaded Poland.


(c)  Appeasement

  • Britain and France never enforced the terms of the Versailles Treaty where the terms were too harsh on Germany.
  • The Anglo-French   policy   of   non-enforcement became a weakness of the Western powers on curbing Germany aggression.
  • Britain still had fresh memories of the carnage of World War 1 to start another war so fear resulted in appeasement.
  • Western  appeasement     encouraged     German aggression and caused the war. Hitler saw that no one would resist his aggression.
  • In the 1930s people believed that Germany was unjustly treated by the Versailles Treaty.
  • So the policy of appeasement was adopted with the hope that the use of force would be avoided.
  • In the 1930s the Western powers realised that the League of Nations was powerless and appeasement became an alternative method of preserving peace.
  • Appeasement encouraged Hitler’s aggression as he became popular with the Germans in and outside Germany.
  • Germany was encouraged in the Anglo-German Naval Agreement of 1935, re-militarisation of the Rhineland of 1938, unification with Austria, and the invasion of Czechoslovakia of 1939.

(d)  The Anschluss (union) with Austria

  • The Versailles  Treaty  terms  did  not  allow  the unification of Germany and Austria although they had the same language and culture.
  • The signatories to the treaty did not realise that union (Anschluss) would be Hitler’s immediate objective.
  • Hitler advanced the ideas in his book, Mein Kampf, to totally reject the terms of the Treaty of Versailles which humiliated Germany.
  • He  advocated  for  the  search  of  a  living  space (lebenstraum) to the east of Germany.
  • In 1938 Hitler invaded Austria and Czechoslovakia.
  • In 1939 he invaded Poland triggering World War 2.

(e)  The Problem of Czechoslovakia

  • Czechoslovakia was created to give freedom to Czech and Slovak minorities in Central Europe.
  • But Czechoslovakia  had  no  Constitution  that guaranteed other minorities their rights and interests. The Czechs and Slovaks had different cultures.
  • Czechoslovakia  became  a  problem  child  of  the League of Nations from its birth.
  • When Hitler came to power as Chancellor he gave moral and  financial support  to  the  Germans  in Czechoslovakia.
  • Hitler  supported   the   German   leader,   Conrad Heinlein,       who    wanted    Sudetenland    to    be independent of Czechoslovakia.
  • France and  Czechoslovakia  had  an  agreement to support each other in the event of an attack. So Britain and France were concerned about the political instability in Czechoslovakia.
  • Hitler gave an ultimatum to Neville Chamberlain (British Prime Minister) that if Sudetenland was not allowed self-government there would be war and Germany would take over Sudetenland.
  • The French and British agreed to let areas with a 50% German population to be incorporated into Germany but Hitler wanted the whole of it to be part of Germany.
  • Britain and France showed that they were afraid of German power and were not prepared for war. This led to the Munich Agreement of September 30, 1938, reached by Germany, Great Britain, France, and Italy:

-     Permitted     German     annexation     of     the Sudetenland in western Czechoslovakia.

-     Recognised the Polish and Hungarian claims against Czechoslovakia.

-     Poland  took  Tuscan  and  Hungary  took  the Southern part of Czechoslovakia and Ruthenia.

-     Czechoslovakia lost valuable communication systems, defensive frontiers and a major industrial area.


Immediate causes


  • The Russo-Germany Non-Aggression Pact on 23 August 1939 gave Hitler the courage to invade Poland, knowing that Russia would not intervene.
  • The invasion of Poland by Germany on 1 September 1939 was the immediate cause of the Second World War.
  • France and  Britain  went  to  war  with  Germany because they had signed an agreement to support Poland in the event of German aggression.

The  main events of World War II


  • The years of the “Lightning War” (Blitzkrieg) up to the defeat of the Germans in Stalingrad (USSR) in 1942 to 1945:

-     Blitz means lightning; Krieg means war.

-     The  Nazis’  method  of  attack  was  called blitzkrieg (lightning war).

-     It  was  called  blitzkrieg  because  it  was  an extremely fast knock-out war.

-     Blitzkrieg meant the rapid advance of hundreds of  tanks  backed  up  by  fighter and  bomber planes.

-     Rapid long distance invasions were possible because of the improvements in the tanks and warplanes used in the First World War.

-     It started with the invasion of Poland in 1939.

  • Britain had given security guarantees to Poland but both Britain and France failed to save Poland which was attacked by two great powers, Germany and Russia.
  • The  USSR  attacked  Poland  from  the  east  and Germany from the west.
  • The  Germans  and  the  Russians  used  superior weapons.
  • Poland was defeated in 17 days.
  • Poland surrendered on 17 September 1939.
  • It was divided between USSR and Germany.
  • For the next six years Poland was non-existent.
  • Britain and France declared war on Germany on 3 September 1939 but they were not ready for war.
  • The USSR took advantage of the war to regain control of  Estonia,  Latvia  and  Lithuania  which had been granted independence by the League of Nations.
  • In a 3 month war called the Winter War, USSR attacked and defeated Finland. The Moscow Peace Treaty was signed in March 1940 giving Russia access to the Baltic Sea through the Gulf of Finland.
  • Latvia, Estonia and Lithuania became part of the USSR until the 1980s.
  • The Soviet Union believed that Germany would attack it since the Nazi had declared communism to be its worst enemy.
  • Britain, the USSR and France feared Germany and did not want to be at war with Germany.
  • Stalin, the USSR President, signed a 10 year non- aggression pact with the Germans on 23 August This was meant to prevent German invasion of the USSR and vice-versa.
    • The world was surprised by this agreement because the two countries were worst enemies.
    • Despite  the  agreement,  Germany  invaded  the Soviet Union and Eastern Poland on 17 September 1939.



    Blitzkrieg in Western Europe


    • Hitler  offered  peace  to  the  Western  powers  in October 1939.
    • The offer was turned down. Germany moved its forces to the western front.
    • The western offensive began on 10 May 1940.
    • The Nazis overran Netherlands, Belgium, Denmark, Norway and Luxemburg.
    • Germany then moved towards France. Britain then began to prepare for war.
    • The  Germans  rolled  over  French  defences  and occupied the country.
    • The blitzkrieg was successful in Western Europe.
    • The Nazis put up a puppet regime in France, the Vichy Government led by Marshal Petain.
    • A  large  number  of  German  troops  and  police occupied France.
    • By conquering France, the Germans took control of the French Empire in Africa, Asia and the Pacific.

    The  Battle of Britain (Operation Sea  Lion)

    • After  defeating  France,  Germany  turned  onto Britain.
    • They   bombarded   the   British   cities   especially London.
    • The British evacuated their major cities to protect their population.
    • Most children in the urban areas were moved to the country side.
    • Technological   advances   in   air   warfare   made millions of civilians to be ready targets.
    • About 51 000 British people were killed in the attack on Southampton.
    • But the Germans were unable to defeat the British in the air.
    • The Germans had more planes than the British, but the British had the advantage of the radar.
    • This  radar  enabled  the  British  to  detect  the movement of German planes every time.
    • The British could then shoot down many German bombers.
    • The Nazis lost 1 733 planes by October 1940.
    • The falling planes were a big problem because they carried bombs which exploded on hitting the ground.
    • By September 1940 the Germans were losing a lot of their fighter planes making it hard to continue their air strikes on Britain.
    • Then the air attacks were called off.

    The  war in Eastern Europe

    • In April 1941 the Nazi attacked Yugoslavia.
    • The Germans took a week to conquer it.
    • The Germans then moved onto Greece which had been under attack by Italy.
    • Hungary, Rumania and Bulgaria, in South Eastern Europe had already fallen under fascist control.
    • By mid-1941 the fascists controlled and occupied almost all of Europe.
    • The German armies attacked the British and were about to conquer Cairo.
    • Then Hitler called back all his troops because he wanted to attack the USSR.
    • In June 1941 the German forces broke the Nazi- Soviet pact by attacking the USSR in what was code-named Operation Barbarossa:

    -     According to the NAZI, the USSR political system was inspired by their two greatest enemies,   namely     Jewry     (Jews)     and Communism.

    -     During Operation Barbarossa, the Soviet Army was forced to retreat.

    -     The Soviets took all machinery and factory equipment with them.

    -     The Germans were faced with the Soviet Union winter and the Nazi troops were not ready for the Russian cold.

    -     The cold and the many Soviet troops halted the Germany army.



    The  war in Asia and  the  Pacific


    • The Japanese joined Italy and Germany in their international fascist alliance, the Rome-Berlin- Tokyo Axis in 1939.
    • In   1941   Japan   occupied   French   colonies   in Southeast Asia, Vietnam and Laos.
    • Japan targeted Britain’s Asian territories for future expansion.
    • The USA and Britain cut off Japan’s supply of oil.
    • The Japanese air force attacked the US Naval base at Pearl Harbour in Hawaii in December 1941.
    • It was this attack that brought the USA into the war on the Anglo-Russian side.
    • In early 1942 Japan attacked the British colonies of Malaya and Singapore.
    • British forces in Singapore surrendered to Japan.
    • About 80 000 British soldiers became prisoners of war.

    Japanese attack on Pearl  Harbour

    • The Japanese were tired of negotiations with the United States. They wanted to continue their expansion within Asia but the United States had placed an extremely restrictive embargo on Japan in the hopes of curbing Japan’s aggression.
    • Rather than giving in to the USA demands, the Japanese decided to launch a surprise attack against the United States in an attempt to destroy the United States’ naval power even before an official announcement of war was given
    • On the morning of December 7, 1941, the Japanese launched a surprise air attack on the USA Naval Base at Pearl Harbor in Hawaii.
    • After just two hours of bombing, more than 2,400 Americans were dead, 21 ships had either been sunk or damaged, and more than 188 aircraft destroyed.
    • The attack at Pearl Harbor so outraged Americans that the USA abandoned its policy of isolationism and declared war on Japan the following day – officially bringing the  United  States  into World War II.

    The  military struggle against Fascism

    • By early 1942 the major powers were embroiled in the war.
    • World War II was a battle of ideologies and armed forces.
    • Within the  Western  countries  and  the  Soviet Union, the forces of capitalism and socialism joined together to fight the authoritarian system of Fascism.
    • Those  Europeans  who  supported  Fascism  were called collaborators.
    • The German position was hopeless. Hitler did not want his troops to surrender but they ignored him and 91 000 German soldiers surrendered to the Soviets during Operation Barbarossa. By this time, about 194 000 Germans had already died.
    • Hitler wanted to destroy the city of Leningrad but it was not easy.
    • His troops surrounded Leningrad and blockaded the shipment of food resulting in  600 000 Soviets dying of starvation and disease.
    • In 1943 the British and Americans invaded Italy.
    • In 1944 the Nazi were beaten back by the Soviets.
    • On 6  June  1944,  the  D-Day,  150  000  Anglo- American forces and 11 000 aircraft opened up the “Western Front” invading the heart of occupied France.
    • From there they made a final push into Germany.
    • By 1945 the Germans were under attack from both sides. The Allied armies finally brought the Nazi war machine to its knees.
    • On 7 May an armistice was signed.
    • Hitler committed suicide because he could not face defeat.
    • Mussolini  was  shot  and  his  body  hung  upside down.
    • 25 million citizens of the USSR were left homeless.
    • More than 1 700 towns and 70 000 villages were destroyed.

    The resistance to Fascism by the ordinary people


    • Passive resistance: If any German person entered a bar or restaurant everyone would pay their bills and leave immediately.
    • People   were   not   violent   but   were   simply uncooperative with the Fascists.
    • If anyone spoke in German language, people would profess ignorance and went quietly on their way.
    • People   formed   underground   organisations   to oppose the Nazi, especially in France.
    • They printed news, painted anti-Nazi slogans on the walls.
    • Resistance groups called ‘partisans’ blew up Nazi military equipment.
    • They assassinated German soldiers.
    • They destroyed infrastructure like bridges and roads needed by the fascists to maintain their supplies.
    • In Yugoslavia, Josip Tito led a group that attacked the fascists.  Josip  Tito’s  partisan  brigades  of 250  000  women  and  men  eventually  became  a “Revolutionary of National Liberation” which set up a government in Yugoslavia.
    • There were 6 200 partisan groups in the USSR.
    • They derailed more than 21 000 trains. They destroyed 1 100 aircrafts, wounded and killed one and a half million Nazi soldiers.
    • Charles de Gaulle set up the Free France Movement in London.
    • Captured partisans were killed as revenge. Keitel, a German General, ordered that for every German soldier killed, 50-100 partisans had to be sentenced to death.
    • In one Yugoslav town 7 300 people including all school children and their teachers were massacred to revenge the killing of a few Nazi soldiers.
    • Aserious resistance was staged in Warsaw, Poland’s capital, in 1944:

    -     46 000 partisans, mainly Jews, led an uprising against the Nazis.

    -     They were poorly armed and fought the Nazis for 63 days.

    -     They received no aid from the USSR.

    -     At least 10 000 soldiers and 50 000 citizens in Warsaw died.

    -     300  000  people  were  sent  to  concentration camps.

    -     The  others  in  Warsaw  were  systematically destroyed.

    • The standard of living was compromised because resources were directed towards the war effort.
    • Many people worked in munitions factories to keep the troops supplied.
    • Women were mobilised to carry out new types of jobs which no one had ever thought could be done by women.

    Final  days of the  war in Asia

    • Fascism was defeated in Europe early 1945 but World War II continued in Asia and the Pacific.
    • In   Burma,   British   troops   fought   against   the Japanese.
    • The British enlisted 120 000 African soldiers to fight for Burma.
    • The Japanese organised ‘Kamikaze’ pilots to crush the US navy. ‘Kamikaze’ pilots were instructed to commit suicide by flying their aeroplanes directly into an enemy ship in order to make it explode.
    • But  ‘Kamikaze’ flights did not  gain victory  for Japan.
    • In 1945 the US began massive bombing of Japanese cities.
    • An attack on Tokyo in March 1945 caused 125 000 casualties and 267 000 buildings were destroyed.
    • The first atomic bombs were dropped on Japanese cities of Hiroshima and Nagasaki in August 1945.
    • The use  of  atomic  weapons  caused  a  lot  of destruction and was a final blow to Japan.
    • On 2 September 1945 Japan surrendered.

    Africa and  World War II


    • Many Africans were conscripted into the armies to fight Fascism in the name of freedom.
    • Britain recruited more than 500 000 Africans for both combat and non-combat roles.
    • Most of the fighting force came from West Africa.
    • Some also came from South Africa and Zimbabwe in Southern Africa.
    • Some were sent to Burma to fight the Japanese.

    Atrocities against the  Jews (Anti-Semitism) 

    • Hitler did not create the German hatred of Jews.
    • He found it there but he perfected it.
    • Hitler  removed  all  Jews  from  the  civil  service, teaching, medicine, law, sports and art.
    • He ordered the isolation and punishment of Jewish shopkeepers and business persons.
    • Jews were forbidden entry into most universities and professions.
    • Jews could not marry or be married to German citizens.
    • On 9 November 1938, a campaign was started to destroy Jewish property:

    -     Jewish synagogues were burnt down.

    -     7 000 Jewish businesses were destroyed.

    -     Thousands of Jews were beaten up.

    -     Government  decreed  that  insurances  would not pay for the damages. Jews were moved into labour camps.

    • The  Germans   built   30   major   concentration camps, including Auschwitz, Treblinka, Dachau, Ravensburg, Buchwald and Sachsenhause.
    • Six million out of eight million Jews who lived in Central Europe in the early 1930s were killed.

    Atrocities against Slavonic people, other minorities and  the  church

    • The Slavonic people of Poland who occupied parts of the USSR were subjected to severe ill-treatment.
    • The S.S Action Team killed tens of thousands of Russians and Poles.
    • Conditions  in  the  prisoner-of-war  camps  were atrocious.
    • The prisoners were herded into exposed barbed wire encampments.
    • They suffered the Russian bitter winter weather.
    • Previously Hitler worked well with the church but later appointed a former army chaplain, Ludwig Muller, to supervise the protestant church.
    • The church protested and Hitler arrested hundreds of the clergy and confiscated their property.
    • In 1937 Pope Pius X1 openly criticised Nazi rule and several catholic priests were arrested.
    • Then the church remained silent against all the evils committed during the war.

    Results of World War II

    • There were huge changes to the political systems and boundaries of European nations.
    • USSR,  Romania,   Poland,   Hungary,   Albania, Czechoslovakia and Bulgaria became socialist countries.
    • Germany was divided into two separate nations, namely the German Democratic Republic (East Germany) and Federal Republic of Germany (West Germany). This division was along the city of Berlin, hence the Berlin Wall.
    • East Germany became a communist country while West Germany became a capitalist state.
    • An increase in the number of socialist states led to a shift in the world balance of power.
    • World War II resulted in a permanent decline of Britain and France as world political powers.
    • The USSR became a super power on the socialist side.
    • The USA became a super power on the capitalist side.
    • The USA was economically stronger than all other capitalist states.
    • The rise of super powers of differing ideologies and political  systems  meant  the  beginning  of an  intensive  rivalry  between  communism  and  capitalism. It became very tense in the 1950s and was called the “Cold War”.
    • International political organisations to  safeguard the peace of the world were established, e.g. the United Nations Organisation (UN) in 1945.
    • Africans   and  Asians   began   to   demand their independence from the colonial powers.
    • The atrocities committed by the Nazis led to the emergence of human rights as an area of great concern in international affairs.
    • Jews got a new homeland, Israel.
    • The   Universal   Declaration   of   Human   Rights (UDHR) was then drafted in 1948.

    The results of World War II can be divided into social, political, economic and technological.