Answer:
the needs of the nation have changed.
Explanation:
The role of the president has evolved over time because the the needs of the nation have changed.
The needs of the nations have changed with time and the President being responsible for the well-being of the nation had to also adjust his roles also to meet the growing needs and demands of the populace.
The factors that led to the surprise strategic attack of Pearl Harbor was due to many reasons, among which the Japanese imperialistic tendencies were the most obvious one. The Japanese really wanted to have control over those portions of the Pacific which is also the reason why they attacked Pearl Harbor.