The long term causes of the war: 1-The treaty of Versailles:In Germany, people resented the Treaty of Versailles, which Hitler had promised to destroy. He broke its conditions, firstly by rebuilding Germany's armed forces. Then in 1936 he reoccupied the Rhineland, an important industrial region which had been made a demilitarised zone by the treaty. 2-The failure of the League of Nations:The League of Nations was created to keep the peace, but it was unable to prevent the Second World War.In general, the organisation failed because it could not enforce treaties or impose its decisions. 3-Expasionism: Authoritarian regimes in Germany, Italy and Japan felt that they needed to expand the territory under their control in order to acquire more raw materials and establish new markets for their exports. They also aimed to increase their international power and influence. 4-Appeasement policies:In order to keep the peace and avoid another war, democracies such as Great Britain supported a policy of appeasement.As a result, they did not use military force to prevent Japanese, German and Italian expansionism in the 1930s. Increasing tensions: During the 1930s, Japan, Italy and Germany took advantage of appeasement and proceeded to annex or invade other countries. -In 1935, Mussolini invaded Abyssinia./ -In 1938, Germany annexed Austria and occupied the Sudetenland region of Czechoslovakia. In March of the following year, Germany invaded and occupied the rest of Czechoslovakia. The outbreak of war: On 23 August 1939, Hitler and Stalin signed the Nazi-Soviet Pact, in which they agreed not to attack each other. They also decided to invade Poland and divide the country between them.In response to the Nazi-Soviet Pact, on 25 August, Great Britain joined France and Poland in an alliance of mutual protection. One week later, Germany invaded Poland and on 3 September 1939, Great Britain and France declared war on Germany. The war's participant and phases: The war was fought by the two oppsing sides: the Axis Powers and the Allied Powers. -The Axis Powers: Germany, Italy, and after 1940, Japan./ -The Allied Powers: initially Great Britain, France and Poland, later joined by members of the Commonwealth like Canada and Australia, the USSR and the United States. First phase: Axis offensives 1939-1941: Europe: Germany had a number of early victories in Europe, occupying Poland, Denmark, Norway, The Netherlands, Belgium, Luxembourg and France. These victories were due to the Germa's blitzkrieg strategy. In June 1941, Germany attacked the USSR, which responded by joining the Allies. Asia and Oceania: Japan invaded several Allied colonies in Asia and Oceania. Then on 7 December 1941, Japanese forces carried out a surprise attack on Pearl Harbor - an important American naval base in Hawaii. As a result, the United States declared war on Japan and entered the conflict. Second phase: Allied victories 1942-1943: Europe: during the 1942-1943 Battle of Stalingrad, German forces occupied the city of Stalingrad in the USSR. The Soviet army counter-attacked and surrounded the German forces. Third phase: final Allied advances 1943-1945: Africa: The allies to cross the Mediterranean and invade Italy. Europe: on 6 June 1944, the Normandy Landings took place in France. Allied troops landed on the beaches of Normandy and began liberating France from German control.After that, the Allies attacked Germany in three directions: from France, Italy and the USSR.In May 1945, the Allies entered Berlin and Germany surrendered. Asia and Oceania: In August 1945, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki. As a result, Japan finally surrendered on 2 September 1945.