Passport to Mexico

A story posted on cnn.com yesterday touts the benefits of traveling to Mexico from the U.S. by car or bus. Among the stated benefits is the following...

All U.S. citizens must have a passport for airline travel to Mexico and the Caribbean. But, those traveling by land or boat need only a driver's license or birth certificate.

http://www.cnn.com/2007/TRAVEL/DESTINATIONS/03/26/mexico.no.passport.ap/index.html

Requiring passports for airline passengers is a security measure put in place last year, presumably to make sure only U.S. citizens get back into the country, and to keep terrorists out. Passports are also now required for cruise ship passengers for this same reason. But if passports are not required for some modes of travel into and out of the country, requiring passports for any other mode is a pointless hassle for well-intentioned travelers. Unless we know for sure that terrorists never travel by car or bus (or boats smaller than cruise ships), there should be outrage at this security loophole and at the inconsistency of enforcement.