Here is the total list of countries that Japan invaded during WW2. They killed 100s of thousands of innocent civilians including children. Rapes in massive scale and other kind of atrocities. Does that count as terrorism to begin with?
Several regions in mainland China - 1938 - 1945
French Indochina (Vietnam, Cambodia and Laos) - July 15, 1940 - August 29, 1945
Hong Kong (UK) - December 12, 1940 - August 15, 1945
Thailand - as an 'allied' state although induced - December 8, 1941 - August 15, 1945
British New Guinea - December 27, 1941 - September 15, 1945
Philippines (USA) - May 8, 1942 - July 5, 1945
Guam (USA) - January 6, 1942 - October 24, 1945
Dutch East Indies - January 18, 1942 - October 21, 1945
Portuguese Timor - February 19, 1942 - September 2, 1945
Malaya (UK)- March 27, 1942 - September 6, 1945
Andaman Islands (India) - March 29, 1942 - September 9, 1945
Singapore (Singapore) - March 29, 1942 - September 9, 1945
Kingdom of Sarawak (UK) - March 29, 1942 - September 9, 1945
Brunei (UK) - March 29, 1942 - September 9, 1945
Borneo (UK) - March 29, 1942 - September 9, 1945
Nauru - August 26, 1942 - September 13, 1945
Wake Island (USA) - December 27, 1941 - September 4, 1945
Burma - 1942–1945
Gilbert Islands (UK) - December 1941 - January 22, 1944
Christmas Island (Australia) - March 1942 - October 1945
Attu and Kiska Islands (US) - June 6, 1942 - September 27, 1943