U.S. Treasury Secretary Paul O’Neill says the specter of terrorism will haunt the country forever. O’Neill spoke this morning to 200 executives in downtown Des Moines.O’Neill says on September 11th, he had to give up being “Peter Pan” and believing the U.S. was “impregnable” to terrorist attack.O’Neill says the September 11th terrorist operation cost only half a million dollars, and he says that’s not a lot of money, or investment, based on the return.O’Neill says it’s that calculation that convinces him the U.S. will be subjected to more attacks. O’Neill says he’d like to able to say we can forget about terrorism, but he says we’re going to have to learn to live with it.