The main reasons for the start of World War II are the Treaty of Versailles harshness on Germany through military limitations and the loss of land, which contained German Speaking people, the policy of appeasement, which allowed Hitler to think he could do whatever he wanted without being stopped, Hitler's aims and policies that included expansion of Germany's territory, persecution of his enemies and the alliances with Japan, Italy and Russia and The Nazi- Soviet Pact that allowed Hitler to gain some land and also be able to prepare for war against Russia.
The Treaty of Versailles was one of the main reasons because the German people resented it mainly because of the war guilt clause, the loss of land and the restrictions on their armed services, which were a national pride. Hitler used these ideas to get into power, “I will tear up the treaty of Versailles”, and that's what he was attempting to do, firstly he re introduced conscription before entering the Rhineland, he joined up with Austria and started to invade and regain the land that had been taken away from them, in turn this lead to war because of the invasion of Poland. The reason Hitler managed to get away with this is because of Britain's Policy of appeasement.
The policy of appeasement was also a main reason for the outbreak of war, this is because it allowed Hitler to do what ever he wanted to do. However this wasn't the only bad thing that it caused, because Britain was appeasing it gave Germany time to re build its armed forces for war, however it also allowed the allies to improve and increase their armed forces as well. If the policy of appeasement hadn't been used Hitler may not of done all the things he did and in turn a second war may have of been avoided.
Hitler's aims and policies created tension across the whole of Europe because of what they feared he would do; control of all of Europe, persecution of all those he didn't like as well as many others. Hitler managed to get away with these policies to start with because many people didn't know about them, some people supported his anti communism views so turned a blind eye on the others, while some didn't care and finally the policy of appeasement allowed him to carry them out without fear of an attack by the allies. The main reason that Hitler went unchallenged by the rest of Europe in his policies for such a long time is that most of the politicians and ordinary public remembered the horrors of the Fist World War so didn't want to go to war again and see the atrocities.
The last main reason for the war is the Nazi-Soviet Pact that was agreed in August 1939. The pact agreed that Germany and Russia would each gain half of Poland and that neither would attack the other, the reason Hitler wanted this pact was so that he could gain Poland without retaliation from Russia and it also gave Germany time to build its armed forces up before the invasion of Russia. However it can be seen that the blame rests on Russia for agree to the pact, this is because without it Hitler may not have entered Poland due to the fear of retaliation. However Russia agreed to it because they gained land, which would protect from an invasion, and it would allow them to improve their armed forces for when Germany finally attempted to attack them.
In conclusion I believe that the main cause of World War II was the policy of appeasement this is because it made Hitler feel like he could do whatever he wanted without being stopped or challenge. If a different policy had been used a smaller war may have been thought at the beginning instead of a big one at the end. The other thing that may have happened is that Hitler may have not carried out his invasions but instead just of concentrated on re building Germany into an economic power.
