What precipitated the U.S. declaration of war on Germany in December of 1941?

The U.S. declaration of war on Germany in December 1941 was primarily precipitated by the Japanese attack on Pearl Harbor on December 7, which led to the U.S. entering World War II. Following this attack, Germany declared war on the United States on December 11, 1941, prompting the U.S. to respond in kind. Additionally, the growing threat of Axis powers and Germany's aggressive military campaigns in Europe contributed to the urgency for the U.S. to formally engage in the conflict.