FIRST SLICE Defense Secretary Leon E. Panetta watches as Marine Corps Gen. James F. Amos, commandant of the Marine Corps, cuts the birthday cake during the Commandant's Marine Corps Ball in National Harbor, Md., Nov. 12, 2011. Panetta helped celebrate the 236th birthday of the Marine Corps with more than 3,000 active duty and retired Marines and their families. SHARE IMAGE: Download Image: Full Size (0.07 MB) Photo By: VIRIN: 686220-G-BRH28-542.jpg Photo Gallery