Pearl Harbor Anniversary. It has been 63 years now since the USA was forced into World War 2. On this day in 1941, Japan attacked the United States at Pearl Harbor without declaring war first. From the History of Japan, "Japan invaded Manchuria in 1931 and set up the puppet state of Manchukuo. In 1933, Japan resigned from the League of Nations. The Japanese invasion of China in 1937 followed Japan's signing of the anti-Comintern pact with Nazi Germany the previous year and was part of a chain of developments culminating in the Japanese attack on the United States at Pearl Harbor, Hawaii, on December 7, 1941. " My thanks to all the Americans who struggled through on that day as well to those from around the world who helped to defeat Japan.