As we learned, fencing in poor soil, flood plains or sand dunes can also be more expensive than effective, in some places because of terrain challenges we decided spending more than $6 million per mile for specialized fence was not the most effective use of resources to better secure that area of border and opted for more agents and technology there instead. In areas dozens of miles from paved roads where we have time to respond to incursions or where we have natural obstacles of mountains and water that already slow, deter or reroute traffic we don't need fence at all. Any successful strategy must rely more heavily on highly trained, dedicated law enforcement officers and better technology tools, key components of the approach we began in the last administration. Since 2001, we have more than doubled the Border Patrol, deployed highly capable manned aircraft and Unmanned Aerial Systems including the Predator aircraft, and installed fixed and mobile surveillance systems. And, the Department of Homeland Security is in the process of developing its plans to deploy additional technology capabilities along key areas of the border to enhance the effectiveness of these agents.

That strategy is working more than a fence alone would, the volume of illegal crossings on the Southwest border is down dramatically from a peak 1.6 million apprehensions in fiscal year 2000 to only about 350,000 apprehensions in 2011. While the threat of violence by drug organizations is real, average violent crime rates in cities along the U.S.-Mexico border are lower than in comparable cities elsewhere in the U.S. Despite the drug violence that has claimed thousands of lives in its sister city to the south, Ciudad Juárez, El Paso recorded only 5 murders in 2010.

As debate continues about how to best ensure our national security it is important to identify the real threats and develop realistic solutions. In the face of constrained budgets, spending billions on unnecessary fences is not viable. If the symbol of the fence in political campaigns keeps us talking about remaining border security challenges and new and creative approaches that will build on the progress to date then it's not all bad. But if it deceives the public into believing in 2,000 miles of wall as a magic solution to the hard problems of three decades of uncontrolled immigration, the only thing being fenced is our common sense.