Military historian and bestselling author Caleb Carr weighs in on the September 11, 2001, terrorist attacks on New York City and Washington, claiming that terrorism should be seen as "a form of warfare" rather than as a crime, as was the common attitude. Carr, who wrote a controversial 1996 article on terrorism in the World Policy Journal espousing this viewpoint, now elaborates on his position in this "history of warfare against civilians." Carr's view is that the United States should be prepared to move forward unilaterally if necessary, rather than trying to assemble an international military coalition. By presenting historical evidence that war against civilians "has always failed," he brings his unique insights to bear on this most pressing of modern-day issues.