Appeasement
History: 

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.
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 co-operation 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, if possible, was to be based on economic sanctions against an aggressor. The policy appeared to be ineffectual when confronted by the aggression of dictators, notably Germany's Remilitarization of the Rhineland and Italy's Benito Mussolini's invasion of Abyssinia.

Invasion of Manchuria: In September 1931, the Empire of Japan, a member of the League of Nations, invaded Manchuria, in northeast China, by claiming that the regional population was not only Chinese but was multi-ethnic. The Republic of China appealed to the League of Nations and to the United States for assistance. The League of Nations Council 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, and the League duly adopted the report in February 1933. In response, Japan resigned from the League and continued its advance into China, with neither the League nor the United States taking 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 during the late 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".

Anglo-German Payments Agreement: The 1934 Anglo-German Payments Agreement stabilised economic relations between Britain and Germany, guaranteeing German interest repayments on bonds arising from World War I reparations and deepening British economic ties to Germany, particularly in the area of trade. Herbert von Dirksen, the German ambassador to Britain, in 1938 characterised the agreement, alongside the 1935 naval agreement, as carrying "the swaying structure of foreign relations [between the UK and Germany] even in critical periods".

Anglo-German Naval Agreement: The 1935 Anglo-German Naval Agreement had Britain permit Germany to begin rebuilding the German Navy, including its U-boats, despite Germany having repeatedly violated the Treaty of Versailles.

Abyssinia crisis: Italian Prime Minister Benito Mussolini had imperial ambitions in Abyssinia. Italy was already in possession of the neighbouring Eritrea and Somalia. In December 1934, there was a clash between Royal Italian Army and Imperial Ethiopian Army troops at Walwal, near the border between British and Italian Somaliland, in which Italian troops took possession of the disputed territory, and about 150 Abyssinians and 50 Italians were killed. Italy demanded apologies and compensation from Abyssinia, which appealed to the League, with 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 since blocking them, it was thought, would provoke war. Albania, Austria and Hungary refused to apply sanctions, and Germany and the United States were not in the League. Nevertheless, the Italian economy suffered. The League considered closing off the Suez Canal, which would have stopped arms to Abyssinia, but thinking that would be too harsh a measure, failed to do so.
Earlier, in April 1935, Italy had joined Britain and France in protest against German rearmament. France was anxious to placate Mussolini 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, British Foreign Secretary Sir Samuel Hoare and 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 as Emperor of Ethiopia. In July the League abandoned sanctions. The episode, in which sanctions were incomplete and appeared to be easily given up, seriously discredited the League.

Remilitarisation of the Rhineland: Under the Versailles Settlement, the Rhineland was demilitarised. Germany accepted that arrangement under the Locarno Treaties of 1925. Hitler claimed that it threatened Germany and, on 7 March 1936, sent the Wehrmacht into the Rhineland. He gambled on Britain not getting involved but was unsure of 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 so. 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, who was invited to negotiate, 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 it put Germany in a powerful strategic position.

Spanish Civil War: Many historians argue that the British policy of non-intervention was a product of the Establishment's anti-communist stance. Scott Ramsay (2019) instead argues that Britain demonstrated "benevolent neutrality" and was simply hedging its bets by avoiding the favouring of one side or the other. The goal was that in a European war Britain would enjoy the "benevolent neutrality" of whichever side won in Spain.

Conduct of appeasement, 1937–1939: In 1937, Stanley Baldwin resigned as Prime Minister. He was replaced by Neville Chamberlain, who pursued a policy of appeasement and rearmament. Chamberlain's reputation for appeasement rests in large measure on his negotiations with Hitler over Czechoslovakia in 1938.

Anschluss: When the German Empire and Austria-Hungary were broken up in 1918, Austria was left as a rump state with the temporary adopted name Deutschösterreich ("German-Austria"), with the vast majority of Austrians wanting to join Germany. However, the victors' agreements of World War I (the Treaty of Versailles and the Treaty of Saint-Germain) strictly forbade union between Austria and Germany without League consent, as well as the name "German-Austria", which reverted to "Austria" after the emergence of the First Republic of Austria in September 1919. The constitutions of both the Weimar Republic and the First Republic of Austria, included the aim of unification, which was supported by democratic parties. However, the rise of Hitler dampened the enthusiasm of the Austrian government for such a plan. Hitler, an Austrian by birth, had been a pan-German from a very young age and had promoted a Pan-German vision of a Greater Germanic Reich from the beginning of his career in politics. He wrote in Mein Kampf (1924) that he would attempt a union of his birth country Austria with Germany by any means possible and by force if necessary. By early 1938, Hitler had consolidated his power in Germany and was ready to implement his long-held plan.
Austrian Chancellor Kurt Schuschnigg wished to pursue ties with Italy but turned to Czechoslovakia, Yugoslavia and Romania (the Little Entente). To that end, Hitler took violent exception. In January 1938, the Austrian Nazis attempted a putsch following which some were imprisoned. Hitler summoned Schuschnigg to Berchtesgaden in February and demanded, with the threat of military action, for him to release imprisoned Austrian Nazis and to allow them to participate in the government.