The relationship between Canada and the United States of America is a strong and very close one. The two countries work together in several areas. One of the most important aspects of their bond is peacekeeping. In my thesis I am going to investigate how Canada and the U.S. together and separately fight terrorism. I will investigate why the United States is at a greater risk and what the differences are between the two countries. It will be interesting to see how the two countries changed after one of the greatest terrorist attacks in 2001.