Beginning today, citizens of the United States, Canada, Mexico, and Bermuda are required to present a passport to enter the United States when arriving by air from any part of the Western Hemisphere.
This new restriction on local international travel is part of the "Western Hemisphere Travel Initiative." Tightening up on travel documentation was a recommendation of the 9/11 Commission that Congress passed into law in the Intelligence Reform and Terrorism Prevention Act of 2004.
To downplay the consequences of this new travel restriction, a Department of Homeland Security press release points out that over 90 percent of U.S. citizens, 97 percent of Canadians, and just about all Mexicans and Bermudans flying to the United States over the past week arrived with passports. But this means that fully 10 percent of Americans who currently travel overseas this way are going to be at least inconvenienced, and at most dissuaded, from doing so.
It's hard to quantify what a marginal restriction on travel like this means, but let's try:
As early as January 1, 2008, the new restriction may apply to citizens entering the U.S. from the Western Hemisphere by land or sea. Air travelers are probably more likely than land or border crossers to have passports so let's assume that 10 percent of all American border crossers lack passports.
To get a rough idea of what this means, in 1999, there were approximately 300 million roundtrips between the United States and Mexico and the United States and Canada, the vast majority of them same-day trips. Let's assume 250 million of them were U.S. citizens. If 1% of these trips don't happen (10% of current non-passport holders) because of the new Western Hemisphere travel restrictions, that's 2.5 million cross-border trips forgone each year, along with the commerce, goodwill, and freedom those trips would have entalied.
What price freedom? Well, let's make it 10 bucks. At that price, using these strictly back-of-envelope estimates, WHTI costs $25 million per year (not counting the cost of administration). The net present value of a $25 million annual expenditure is $500 million (at a 5% interest rate). In other words, more than half-a-billion dollars (a low estimate) worth of freedom and commerce goes down the drain starting today.
It would be worth every penny if it improved our national security by a similar margin. Alas, it does not.
The reason why requiring passports at borders provides so very little security boils down to the fact that identity does not reveal intention.
In our daily lives, we use identity to assure ourselves of the bona fides of others - neighbors, coworkers, stores, and restaurants, for example. But terrorists and hardened criminals are not similarly constrained by the social and legal pressures we can bring to bear on our law-abiding neighbors.
You could have perfect knowledge of who everyone is - lock down everyone's identity with a mandatory cradle-to-grave biometric tracking system - and you would still not prevent crime and terrorism. I have carefully analyzed the utility of identity for security in my book, Identity Crisis.
Terrorists can defeat an identity-based security system either physically or logically. They can enter the country someplace other than a border crossing for example - and the half-billion expendture on WHTI is 100% wasted. A logical evasion of identity-based border security is to enter the country legally, not having participated in terrorism planning or acts before. This was the technique used by al Qaeda with most of the 9/11 terrorists.
Checking passports at the border of the country is what security expert Bruce Schneier correctly calls "security theater." It may make you feel safer, but it doesn't make you safer. It does corral law-abiding citizens into the habit of showing ID as they go about their business, and it puts information about law-abiding travelers into government data stores for who-knows-what future use.
With the travel restrictions going into effect today, America does not get safer, just smaller.