ON JUNE 7, 1942, Japan invaded Alaska.

On June 10, 1942, the U.S. Navy denied that it happened: “None of our inhabited islands or rocks are troubled with uninvited visitors up to this time.”

The Japanese invasion and occupation of the Aleutian Islands in Alaska was shrouded in secrecy. This secrecy was not only for security reasons but also to avoid provoking a widespread panic across the United States and to avoid acknowledging the fact that the westernmost section of Alaska was now part of Japan’s quickly expanding empire.

Decades after World War II, the U.S. government kept the documents about the Japanese invasion of Alaska classified, and the Americans who were there when it happened didn’t want to talk about it.

Because of this silence, one of the bloodiest and deadliest hand-to-hand combat battles between the United States and Japan was virtually forgotten. This is the story they didn’t want you to know.