Swiftboat Veterans for the Truth spokesman John O'Neill dared Sen. John Kerry on Sunday to sue him for libel if, as Kerry's presidential campaign maintains, key claims in O'Neill's book "Unifit for Command" are not true. "I invite him to sue me for libel," O'Neill, who co-authored the overnight bestseller with Jerome Corsi, told WABC Radio's Monica Crowley. "If he was actually in Cambodia on Christmas Eve and Christmas Day he should sue me. If, in fact, those other five [Swift]boats, on March the 13, [1969], if they all fled like he did, instead of staying like he knows...