What caused the outbreak of World War Two in 1939?

Historians acknowledge many factors causing the outbreak of war in 1939, however it is a culmination of these factors that must be seen as the ultimate cause in triggering the beginning of World War Two. It is neccesary to consider Germany's internal situations in the period following the end of World War One, as well as their international relationships, in order to decipher how the beginnings of the 1939 conflict began. Firstly, one might look to the problems in Germany faced after WW1 caused by the Treaty of Versailles, one clause of which being the requirement to pay reperations; they owed 132 billion gold marks to countries damaged by the first war. Arguably, this did not cause large economic issues since Germany was enjoying a period of strong economic recovery in the period leading up to WW2, however this is debatable. Despite this, they did cause a great burden during the Great Depression, as seen in issues such as hyperinflation, which would have been remembered by many Germans. It can also be argued that reperations were seen as humiliating since they did not see themselves as to blame for WW1; the Treaty of Versailles also included a war guilt clause, which many were angry about. Furthermore, the treaty took away some of Germany's land and enforced a period of disarmament, giving more cause for anger. Hitler's promise to destory the clauses of this Treaty led many to support his claims for war.  Internationally, the spread of communism in the east meant that countries such as America and France were willing to rebuild the relationship between themselves and Germany in an attempt to stop the spread further. This meant that Germany were allowed to take up arms once again without resistance. Chamberlain, the new prime minister of Britain in 1937 wanted to appease Germany as to prevent more conflict, which was looking likely in the years approaching 1939. The Munich Agreement of 1938 is an example of this, giving Germany back some of the lands taken away through the Treaty of Versailles. When Hitler invaded Czechoslovakia in 1939, a part of the Agreement was broken and war followed. Futhermore, international tensions were created by Hitler's hostility towards ethnic minorities. The impression that the German race was superior was shared by many within Germany, Hitler's aim to create a bigger living space for this 'superior' race needed to be revoked.