Illegal immigrants and the Mexican threat to National Security

Here's a quote from a 2006 USAWC Project study entitled, "Illegal Immigration: Is it a threat to National Security?":

Illegal immigration is a concern that poses a serious threat to national security. In the broadest sense, it sends a dangerous message that to the U.S. Government: its laws do not matter, it is incapable of enforcing its borders, and it cannot protect its citizens. Illegal immigration has been shown to provide cover for terrorist opportunities, spur growth in crime, and strain social resources. Although illegal immigrants come from numerous origins, the vast majority of illegal immigrants come from Mexico. Illegal immigration from Mexico has several root causes stemming from Mexican criminal elements exploiting flaws in U.S. immigration law enforcement, Mexican economic depression, Mexico’s disregard for U.S. rule-of-law, and Mexican society along with the Mexican government waging a comprehensive information campaign against the U.S.

Fear Mexico.