During the nearly five years that I was secretary of defense, 2,621 immigrants serving in the United States military became naturalized citizens while deployed to Iraq or Afghanistan. More than 100 immigrant troops have made the supreme sacrifice in combat during those wars. In that same period, from 2006 to 2011, a total of 45,700 immigrants who wore the uniform of the American military all across the world became American citizens.

I was honored to serve alongside all of them, and humbled by their sense of duty, by their willingness to risk life and limb for a country they yearned to call their own.