Righter than you knew. The principle reason for removing ethnic Japanese from the west coast was that riots were already starting to happen within days of Pearl Harbor.
The story you THINK you know is largely a fabrication by lawyers seeking compensation (and fat fees) from Congress in the 1980s.
The book is Magic: The Untold Story of U.S. Intelligence and the Evacuation of Japanese Residents from the West Coast During Ww II by David B. Lowman -- available from Amazon or Alibris.
Lowman was a former high level officer in the National Security Agency and a witness before congressional committees dealing with the evacuation he was uniquely qualified to tell this story. It touches closely on the American codebreakers' success in reading Japanese radio codes, hence the name. Until crucial documents were declassified he couldn't write this book, and consequently it was published posthumously.
Thank you. Great summary!
My father knew many of the growers/horticulturalists who lived in the San Francisco Bay Area. When they were taken off to camps he held their lands in escrow until they returned after the war. He was given in gift some precious bonzai that were his proudest possession until his death. And, by the way, one of Japan’s spies was a nurseryman who lived off of Mountain Boulevard in Oakland.