Peace of mind is not the only thing to have been shaken by the events of Sept. 11. Language has been, too -- or at least our casual assumption that we know what we mean by the words we use.
Take the word at the heart of the matter: "terrorism." We know what was meant on Tuesday, when Japan's central government asked local officials to intensify their antiterrorism efforts, especially against chemical or biological attacks. We knew what the word meant when Aum Shinrikyo unleashed sarin on Tokyo's subways in 1995. And Americans, indeed decent people everywhere, have no doubt that the word applies to the murderous attacks of Sept. 11.
"A group of people commandeered airliners and used them as guided missiles against thousands of people," one U.S. television executive said. "If that doesn't fit the definition of terrorism, what does?"