When Should Have the US Declared War in WWII?

On December 7, 1941, Pearl Harbor was bombed by Japan. Hideki Tojo ordered the attack on November 5, 1941. The US military knew about the attack, but they didn't where. Before the bombing, President Roosevelt set up the US's neutrality. However, Roosevelt declared war on Japan after Pearl Harbor. Three days later, Germany and Italy declared war against the United States. I believe the United States did not do the right thing. They should have declared war against the Axis Powers a couple of months after the bombing of Pearl Harbor.
The army was not adequately prepared at the time of declar…