[Photo] Earlier this month, I wrote about the new border-crossing requirement we’ll be instituting tomorrow, January 31. We’re replacing the outmoded honor system of oral declarations at our border with a common-sense requirement of tangible documentation.

Most Americans might find it hard to understand why, in our post-9/11 world, our country even has a system that allows anyone -- including potential terrorists, convicted felons, and illegal aliens -- to cross our border simply by declaring who they are and where they’re from without having to prove it.

They’d be surprised to learn that even when proof of citizenship and identity are required, more than 8,000 different documents are accepted, including easily forged student library cards and foreign baptismal certificates.

And they would be dismayed by the fact that in spite of the 9/11 Commission’s recommendation that we take serious steps to identify who is crossing our border, our government faces mounting pressure from critics who strongly oppose replacing the current system.

We understand the concerns about commerce. We want commerce. But we can’t ignore the continued threat we face from dangerous people seeking entry.

They’re also ignoring the fact that -- as evidenced by last year’s immigration debate -- the American people rightly oppose open borders, care deeply about border security, and view secure ID as a national imperative.

And they seem unaware of the incongruity of building border fences to stop people from sneaking through America’s back door while failing to check adequately who’s walking through our front door.

Critics charge that our actions will harm commerce by slowing the processing of arriving travelers. In fact, with consistent identity and citizenship documents that are easily recognizable to our CBP officers, we expect processing speed to increase.

We’re also accused of springing these changes on people with little warning. On the contrary, we first gave notice to travelers and border communities in June of last year. We’ve since engaged in a sustained outreach campaign from regular briefings with stakeholders to participation in multiple media interviews. To this day, our outreach efforts continue. And starting tomorrow, when we begin implementation, we’ll do it in a flexible way, treating travelers with understanding and patience as they acclimate.

Michael Chertoff