[gundog]

Not sure I’d make that connection. Facilities for defense were set up well before the “battle”. Roosevelt signed the EO authorizing the internment a few days prior to the false alarm. The Oregon coast has many remnants of WW2 contingency infrastructure.

[Tell It Right]

If you look at the micro-details, FDR's EO was mainly from the WW1 experience of German spies causing the Black Tom explosion in New Jersey. The idea was to keep an eye on the Japanese in case they might plan do the same thing during WW2, and if so be ready to hold them.

But before the Battle of Los Angeles ne Japanese were removed from "military zones".