“Fortress America” is a derogatory term that usually refers to extreme forms of isolationism. Last week, however, CNN anchor Fareed Zakaria gave the idea a new and equally disturbing twist. In a thought-provoking column in the Washington Post, Zakaria described how excessive concerns for security are making the United States more “imperial” in appearance than the old colonial empires, with embassies, public buildings, and even the U.S. Capitol itself surrounded by barricades, moats, or fortifications.