Failure of collective security
"Appeasement policy, the policy of appeasing Hitler and Mussolini, operating jointly at that time, during 1937 and 1938 by continuous concessions granted in the hope of reaching a point of saturation when the dictators would be willing to accede to international collaboration. ... It came to an end when Hitler seized Czechoslovakia on March 15, 1939, in defiance of his promises given at Munich, and Prime Minister Chamberlain, who had championed appeasement before, decided on a policy of resistance to further German aggression."
Walter Theimer (ed.), The Penguin Political Dictionary, 1939
Chamberlain's policy of appeasement emerged from the failure of the League of Nations and the failure of collective security. The League of Nations was set up in the aftermath of World War I in the hope that international cooperation and collective resistance to aggression might prevent another war. Members of the League were entitled to the assistance of other members if they came under attack. The policy of collective security ran in parallel with measures to achieve international disarmament and where possible was to be based on economic sanctions against an aggressor. It appeared to be ineffectual when confronted by the aggression of dictators, notably Germany's Remilitarization of the Rhineland, and Italian leader Benito Mussolini's invasion of Abyssinia.
Invasion of Manchuria
In September 1931, Japan, a member of the League of Nations, invaded Manchuria in northeast China, claiming that its population was not only Chinese, but was a multi-ethnic region. China appealed to the League and the United States for assistance. The Council of the League asked the parties to withdraw to their original positions to permit a peaceful settlement. The United States reminded them of their duty under the Kellogg–Briand Pact to settle matters peacefully. Japan was undeterred and went on to occupy the whole of Manchuria. The League set up a commission of inquiry that condemned Japan, the League duly adopting the report in February 1933. In response Japan resigned from the League and continued its advance into China; neither the League nor the United States took any action. However, the U.S. issued the Stimson Doctrine and refused to recognize Japan's conquest, which played a role in shifting U.S. policy to favour China over Japan late in the 1930s. Some historians, such as David Thomson, assert that the League's "inactivity and ineffectualness in the Far East lent every encouragement to European aggressors who planned similar acts of defiance."
In this 1935 pact, Britain permitted Germany to begin rebuilding its navy, including its U-boats, in spite of Hitler already having violated the Treaty of Versailles.
Italian Prime Minister Benito Mussolini had imperial ambitions in Abyssinia. Italy was already in possession of neighboring Eritrea and Somalia. In December 1934 there was a clash between Italian and Abyssinian troops at Walwal, near the border between British and Italian Somaliland, in which Italian troops took possession of the disputed territory and in which 150 Abyssinians and 50 Italians were killed. When Italy demanded apologies and compensation from Abyssinia, Abyssinia appealed to the League, Emperor Haile Selassie famously appealing in person to the assembly in Geneva. The League persuaded both sides to seek a settlement under the Italo-Ethiopian Treaty of 1928 but Italy continued troop movements and Abyssinia appealed to the League again. In October 1935 Mussolini launched an attack on Abyssinia. The League declared Italy to be the aggressor and imposed sanctions, but coal and oil were not included; blocking these, it was thought, would provoke war. Albania, Austria, and Hungary refused to apply sanctions; Germany and the United States were not in the League. Nevertheless, the Italian economy suffered. The League considered closing off the Suez Canal also, which would have stopped arms to Abyssinia, but, thinking it would be too harsh a measure, they did not do so.
Earlier, in April 1935, Italy had joined Britain and France in protest against Germany's rearmament. France was anxious to placate Mussolini so as to keep him away from an alliance with Germany. Britain was less hostile to Germany and set the pace in imposing sanctions and moved a naval fleet into the Mediterranean. But in November 1935, the British Foreign Secretary, Sir Samuel Hoare and the French Prime Minister, Pierre Laval, had secret discussions in which they agreed to concede two-thirds of Abyssinia to Italy. However, the press leaked the content of the discussions and a public outcry forced Hoare and Laval to resign. In May 1936, undeterred by sanctions, Italy captured Addis Ababa, the Abyssinian capital, and proclaimed Victor Emmanuel III the Emperor of Ethiopia. In July the League abandoned sanctions. This episode, in which sanctions were incomplete and appeared to be easily given up, seriously discredited the League.
Remilitarization of the Rhineland
Under the Versailles Settlement, the Rhineland was demilitarized. Germany accepted this arrangement under the Locarno Treaties of 1925. Hitler claimed that it threatened Germany and on 7 March 1936 he sent German forces into the Rhineland. He gambled on Britain not getting involved but was unsure how France would react. The action was opposed by many of his advisers. His officers had orders to withdraw if they met French resistance. France consulted Britain and lodged protests with the League, but took no action. Prime Minister Stanley Baldwin said that Britain lacked the forces to back its guarantees to France and that in any case, public opinion would not allow it. In Britain, it was thought that the Germans were merely walking into "their own backyard". Hugh Dalton, a Labour Party MP who usually advocated stiff resistance to Germany, said that neither the British people nor Labour would support military or economic sanctions. In the Council of the League, only the Soviet Union proposed sanctions against Germany. Hitler was invited to negotiate. He proposed a non-aggression pact with the Western powers. When asked for details he did not reply. Hitler's occupation of the Rhineland had persuaded him that the international community would not resist him and put Germany in a powerful strategic position.
Spanish Civil War