As former Homeland Security Secretary Janet Napolitano pointed out, if you build a 50-foot wall, you'll soon be confronted with a 51-foot ladder. You need a strategy that involves layered defense: deployed patrols, sophisticated sensor equipment, and surveillance from the air. That is what has had a positive impact over the last generation.

People should remember that Mexican migration is now at a net negative. More Mexicans are leaving through deportation and voluntary return than are entering the United States legally and illegally.

Until we have a legitimate labor market between Mexico and the United States, people will attempt to come here to work.

We must recognize that this massive economic bloc that's emerging in North America cannot be accomplished unilaterally. It must be accomplished in partnership with Mexico and Canada. And we have to work together to secure the continent in order to keep dangerous people and dangerous things out and strengthen perimeter security on a continental basis.

In the course of 25 years, we have developed a constructive relationship with Mexico that was nonexistent before. During the last eight to 10 years there have been continued efforts which have resulted in a strategic alliance with the Mexicans and improved safety and security at the border.

Mexico now has the 13th largest economy in the world. The Organization for Economic Cooperation and Development predicts it will have a larger economy than Germany by 2042.

Our security in a global world must be looked at on a continental basis.