The united States entered world war 2 because of what?

The United States entered World War II primarily due to the Japanese attack on Pearl Harbor on December 7, 1941, which resulted in significant loss of life and damage to the U.S. Pacific Fleet. This attack galvanized public and political support for entering the war, leading Congress to declare war on Japan the following day. Subsequently, Germany and Italy declared war on the U.S., solidifying America's involvement in the global conflict.