On December 8, 1941, the United States government declared war on Japan and entered World War II. Japanese troops landed in French Indochina (Vietnam, Laos, Cambodia), the Philippines, and British Singapore. By April 1942, Japanese forces had occupied the Philippines, Indochina, and Singapore.
Following are the areas that Japanese forces militarily invaded and occupied during World War II.
・Almost all the coastal areas of the Republic of China
・U.S. territories in the Philippines
・British Hong Kong
・British North Borneo (now part of Malaysia)
・British Protectorate of Sarawak (now part of Malaysia)
・British Malaya (now Malaysia and Singapore)
・Dutch East Indies (now Indonesia)
・British Burma (now Myanmar)
・U.S. territory islands in the Western Pacific (Guam, Wake Island, etc.)
・Australian territory of Papua (now Papua New Guinea)
・British West Pacific islands (Solomon Islands, Gilbert Islands, Ellice Islands, etc.)
・Part of the Aleutian Islands, Alaska Territory, U.S.A. (Atka Island, Kiska Island)
Except for the coastal area of China, all regions and countries that Japan invaded during World War II were originally occupied or colonized by European countries or by the United States. Some states in Asia have never been colonized by any European countries, the U.S., or Japan. Thailand is a well-known example of a country that has never been invaded during its history. China was, and still is, a huge nation, and only the coastal area was invaded during World War II, while the area known as Manchuria had been colonized by the Japanese Empire before World War II began.
Following are the countries and regions that Japan invaded before World War II.
The Pacific islands formerly colonized by Germany, such as the Bismarck, Mariana, Marshall, and Palau Islands, became Japan’s colonies as a result of a treaty signed after World War I. Japan acquired these colonies without “invading” them.