In my point of view both the Munich Agreement and the invasion lead to the beginning of World War 2. But the main cause of the war was the invasion of Czechoslovakia in 1939. Both of these incidents clearly show that both UK and France and the German leader Hitler could not be trusted anymore.
Furthermore, it is clearly seen that the invasion of Czechoslovakia was the main event leading to the war because it made Hitler think he could do anything he wanted. It also gave him most of the resources in Czechoslovakia, which also showed that both UK and France were afraid of Germany and couldn't do anything but just let Germany invade. On the other the Munich agreement gave Hitler Czechoslovakia's defenses so they didn't have any army to defend themselves.
Secondly, Hitler occupied the rest of Western Czechoslovakia. This broke the Munich Agreement. Chamberlain realized that Hitler could not be trusted and Britain also promised Poland that they will help them if they were invaded by any foreign country but It was obvious that Poland would be next on Hitler's list as the Polish Corridor had been taken away from Germany at the Treaty of Versailles.
World War Two began after Britain declared war on Germany on September 3rd, 1939 after Hitler had invaded Poland 2 days ago. There are two things happened before, Munich Agreement and the invasion of Czech, which convinced Hitler and eventually causing the war.
The Munich Agreement was signed on September 29th, 1938. Britain and France agreed to give Hitler Sudetland where he got Nazis in there to riot to force the government to give Germany Sudetland. France and Britain agreed to give him because, firstly, there were germen living in that piece of land even though the whole...