During the months that followed the attack on Pearl Harbor, detention camps were built and filled with Americans of Japanese decent. Furthermore, Japanese expatriates aided the Imperial Army’s takeover of Luzon, as those living in the area of Port Arthur had, 37 years earlier, aided the Imperial Navy’s bringing Russia to terms at the Portsmouth Naval Base in Kittery, ME.
I conjecture that, at this time, FDR twice applied his warning “The only thing to fear is fear[‘s distractive nature] itself”: first, by continuing to withhold any witness of what had occurred during the Imperial Army’s march to and occupation of Nanjing; and secondly, by withholding a newly acquired recognition that, not detaining those of Japanese descent living on the West Coast would have seriously risked a total loss to the Axis. That risk being unabated were even 100% of those being considered for detention known to be patriotic. Forget any active risk; there had been a far more dangerous passive risk in leaving them as they were.