Italy and Japan suffered from too many people and too few resources after World War I. They eventually tried to solve their problems by expansion of their territories. In the 1930s there were two incidents which really tested the ability of the League of Nations; the invasion of Abyssinia and Manchuria. The first major test for the League came when the Japanese invaded Manchuria in 1931. The depression had hit Japan severely; the collapse of the American market put the Japanese economy into further crisis. The army leaders of Japan came to a unanimous decision they had to build up an empire by force. Their window of opportunity came in September 1931; they claimed the Chinese soldiers had sabotaged the South Manchurian Railway. In retaliation the Japanese overran Manchuria and threw out all Chinese forces. The following year Japanese aeroplanes and gun ships bomber Shanghai under orders from the Army not the civilian government. It was rather clear who was in control. As expected China appealed to the League of Nations. Japan in its defence claimed it was not invading as the aggressor but simply settling a local difficulty. This was a difficult decision for the League, Japan was a key player, however they were clearly in the wrong. The decision was not going to be an easy one. A full year after the invasion they finally came to a decision. Japan had acted unlawfully and Manchuria should be returned to China. Japan the resigned from the League with plans to invade more of China. The League was powerless, it could not do anything without the help of the USA and USSR, and they weren’t even members of the League. Consequently Japan was able to invade Jehol and faced on opposition from the League.
The Leagues inability to effectively keep peace was once again demonstrated when Italian dictator Mussolini invaded Abyssinia. Like Japan Italy was a key member of the League and wanted to expand territory by invading another country. However unlike Manchuria the League could not argue that Abyssinia was in an inaccessible part of the world. Britain and France wanted to keep Italy happy as without it they would be powerless against Hitler. However although they imposed sanction against Italy they made a fatal error of not closing the Suez Canal. Had they of done this they could have ended the campaign very quickly. Italy continued to ignore orders from the League and by May 1936 Italy had gained the capital of Abyssinia, Addis Ababa. The League had failed. Britain and France thought if they handled the crisis well they would be in a stronger position against Germany. However they could not have been more wrong and in November 1936 Hitler and Mussolini signed an agreement of their own called the Rome-Berlin Axis.
These two failures clearly demonstrated to Hitler that the League was powerless. He would be able conquer other countries and no one would be willing to intervene.
After Hitler took power, he began to build up Germany's armed forces in violation of the Treaty of Versailles. In 1936, Hitler sent troops into the Rhineland, a region of Germany along the banks of the Rhine River. Under the treaty, the Rhineland was to remain free of troops. In March 1938, German soldiers marched into Austria and united it with Germany. Many people in Germany and Austria welcomed that move.
The League of Nations proved incapable of stopping Hitler. It lacked an army and the power to enforce international law. The United States had refused to join the League or become involved in European disputes. Great Britain and France were unwilling to risk another war so soon after World War I. The two powers knew they would bear the burden of any fighting.
Hitler prepared to strike again soon after Germany acquired Austria in March 1938. German territory then bordered Czechoslovakia on three sides. Czechoslovakia had become an independent nation after World War I. Its population consisted of many nationalities, including more than 3 million people of German descent. Hitler sought control of the Sudetenland, a region of western Czechoslovakia where most of the Germans lived. Urged on by Hitler, the Sudeten Germans began to will for union with Germany.
Czechoslovakia was determined to defend its territory. France and the Soviet Union had pledged their support. As tension mounted, Britain's Prime Minister Neville Chamberlain tried to restore calm. Chamberlain wished to preserve peace at all cost. He believed that war could be prevented by meeting Hitler's demands. That policy became known as appeasement.
Chamberlain had several meetings with Hitler during September 1938 as Europe teetered on the edge of war. Hitler raised his demands at each meeting. On September 29, Chamberlain and French Premier Edouard Daladier met with Hitler and Mussolini in Munich, Germany. Chamberlain and Daladier agreed to turn over the Sudetenland to Germany, and they forced Czechoslovakia to accept the agreement. Hitler promised that he had no more territorial demands.
The Munich Agreement marked the height of the policy of appeasement. Chamberlain and Daladier hoped that the agreement would satisfy Hitler and prevent war - or that it would at least prolong the peace until Britain and France were ready for war. The two leaders were mistaken on both counts.
The failure of appeasement soon became clear. Hitler broke the Munich Agreement in March 1939 and seized the rest of Czechoslovakia. He thereby added Czechoslovakia's armed forces and industries to Germany's military might.
In August 1939 arch enemies Hitler and Stalin drew a pact together. Stalin knew that Hitler would turn all his military might toward him, signing the pact brought him extra time and allowed him to build up him military forces. He also believed that Britain and France would not be strong reliable allies against Hitler. Not only did the pact give Stalin time, he also acquired new land which Hitler had conquered.
On September 1st 1939 the Germany army invaded Poland from the west and on the 17th Soviet forces attacked from the east. Poland was conquered. Hitler was given and ultimatum, he was ordered to get out of Poland. However he did not agree, hence Britain and France declared war on Germany on the 2nd September 1939. Hitler had started a war, but it was not the war he had in mind. It was too soon and against the wrong opponents. Hitler had taken one gamble too many.
Although Hitler caused WW2 by refusing to leave Poland there and other factors which contributed. I strongly believe had the USA joined the LON it would not have been so powerless and insignificant. They may well have been able to stop Hitler way before. In addition the LON was unfair towards the Germans it served as a constant reminder of their humiliating defeat and was sooner or later someone was going to do something about it. Thirdly had Hitler not made the pact with Stalin Germany would may well have had to fight a war on two front again and could well have been pulverised.