Question

why does roosevelt use repetition in his request for a declaration of war?
to highlight his own credibility
to provide alternative courses of action
to compare the experiences of countries
to emphasize the threat posed by japan

Explanation:

Roosevelt used repetition to drive home the seriousness of Japan's actions and the threat it posed. By repeating key - points about Japanese aggression, he wanted to ensure the Congress and the public understood the gravity of the situation.

Answer:

to emphasize the threat posed by Japan