It is no cliché to argue that the terrorist attack that befell the United States in September 2001 was a climacteric event, a watershed in the post–Cold War world. Henceforth, all analyses of American na- tional security policy will demarcate events as having occurred either before or after the horrendous events of that day.
Greenberg, Myron A.
"Assessing the Threats,"
Naval War College Review: Vol. 56
, Article 15.
Available at: http://digital-commons.usnwc.edu/nwc-review/vol56/iss1/15