Adolf Hitler was an evil person. Of course, there were several assassination attempts on him and each of them would alter history profoundly. One such attempt was in 1938, in which conspirators, supported by British Prime Minister Neville Chamberlain. The plan was to assassinate Hitler in the possibility that, in 1938, he may invade the Sudetenland. Of course, in OTL, the annexation of the Sudetenland was peaceful and the conspiracy was called off, while many of its members became part of the German Resistance. However, the conspirators hated Hitler and it is entirely possible that the conspiracy may occur against Chamberlain's orders.
POD and aftermath
Despite Chamberlain calling off the assassination, the conspirators' hatred of Hitler lead to the German Civil War. The opening battles of the war were astoundingly in the Nazi's favour. However, in 1940, the tide turned in the favour of the Free Germans. In 1942, the war ended with Germany being restored to its 1919 borders. However, during the same duration of the German Civil War, the Pacific War was raging. Japan conquered much of East and Southeast Asia in the war, but following the Pearl Harbor attack in 1941, the American powerhouse and most of Europe began a total war campaign on Japan. In 1942, Japanese control extended to parts of India. However, post-war Germany also declared war on Japan, pointing war to the favour of the Allies. In 1943, all of Japan except for Japan proper was under Allied control. However, an Allied invasion of Japan known as D-Day began, with starved Japan having fallen to the Allies at last. Japan was made a republic, with the Emperor of Japan committing seppuku. Post-war, decolonization began. However, the colonial powers were still powerful. A spark was needed to bring the world's colonies into revolution. Muhammed Ali Jinnah declared India independent in 1945. In the Indian War of Independence, the spark was lit and the Decolonization Wars began.