Homeland Security Secretary Michael Chertoff responds to criticism of the Department’s new policy requiring proof of citizenship for people crossing the border, including the northern border. Members of Congress from northern border states have demanded that DHS rescind the policy, asserting that it could harm trade.

“Most Americans,” Chertoff writes on the DHS blog, “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.”