Who authorized the attacks on Pearl Harbor, and what was the motivation behind these attacks?

The Japanese Empire under Tojo and the navy under Admiral Yamamoto

Explanation:

The Japanese were pursuing a policy of expansionism in the Pacific that needed them to create strings of defensive islands in the pacific to protect their conquered territories that provided all the resource needed to fuel this maritime power. The US pacific fleet was the only threat to this expansionism, and by hoping that a large surprise attack would quickly destroy the American fleet, causing them to surrender, make peace, and resume trading, the Japanese attacked pearl harbour

I think its Vice Admiral Chuichi Nagumo