Canadian Minister of National Defense Peter MacKay, left, greets U.S. Defense Secretary Robert M. Gates upon his arrival at the Citadel in Halifax, Nova Scotia, Nov. 20, 2009. Canadian Minister of National Defense Peter MacKay, left, greets U.S. Defense Secretary Robert M. Gates upon his arrival at the Citadel in Halifax, Nova Scotia, Nov. 20, 2009. SHARE: Download: Full Size (5.58 MB) Tags: Photo Essays Credit: VIRIN: 007369-C-GFT86-604.jpg Photo Gallery