Final answer:
The central idea in Roosevelt's 'Address to Congress Requesting a Declaration of War' is that the United States should declare war with Japan due to a series of attacks. Roosevelt develops this idea by describing the attacks and emphasizing the need for action and allies' support.
Step-by-step explanation:
The central idea in Roosevelt's 'Address to Congress Requesting a Declaration of War' is that the United States should declare war with Japan due to a series of attacks in other parts of the world over a period of months. Roosevelt believed that these attacks showed Japan's intent to engage in war.
Roosevelt develops this central idea by describing recent attacks on the United States and in the Pacific that prove the Japanese wants to engage in war. He emphasizes the need for the United States to take action and declares that a state of war exists between the United States and the Japanese Empire.
Furthermore, Roosevelt focuses on the need for the support of the United States' allies to be successful in war with Japan. He mentions the cooperation between the United States and Britain, and the decision to prioritize defeating Germany first.