Why wouldn’t a national ID card improve security?
ID documents do not reveal anything about evil intent.Even with a reliable list of terrorists, the authorities will miss anyone who is not previously known to be a threat.The only solution for that is improved intelligence and old-fashioned law enforcement techniques involving the investigation of known evidence.Even where a person is known to be a threat, determined terrorists will always be able to obtain fraudulent documents (either counterfeit or real documents bought from corrupt officials).Thousands of fraudulent driver’s licenses, for example, have been issued through bribed state employees and identity-theft rings that include such employees.
