Whereas the successful prosecution of the war requires every possible protection against espionage and against sabotage to national-defense material, national-defense premises, and national-defense utilities as defined in section 4, act of april 20, 1918, 40 stat. 533, as amended by the act of november 30, 1940, 54 stat. 1220, and the act of august 21, 1941, 55 stat. 655 (u. s.c., title 50, sec. 104). what assumption is roosevelt making in this paragraph? the us is under threat of espionage and sabotage. japanese americans pose a threat to national security. acts of espionage are most likely already happening. sabotage of national-defense premises have occurred.