Awarded to units of the U.S. Navy and Marine Corps and allies for extraordinary heroism in action against an armed enemy on or after December 7, 1941 (marking the Japanese attack on Pearl Harbor and the U.S. entrance into World War II). The unit must display such gallantry, determination, and esprit de corps in accomplishing its mission under extremely difficult and hazardous conditions so as to set it apart from and above other units participating in the same campaign. The award is the unit equivalent of a Navy Cross Medal and was established on February 6, 1942. To distinguish between the two versions of the Presidential Unit Citation (The Army/Air Force versions versus the Navy version), the Navy version is typically referred to as the Navy and Marine Corps Presidential Unit Citation while the Army and Air Force refer to the decoration simply as the Presidential Unit Citation.