But testifying before the Senate Intelligence Committee in February, Deputy Homeland Security Secretary James Loy said Al Qaeda leaders have considered infiltrating terrorists across the Mexican border because they "believe illegal entry is more advantageous than legal entry for operational security reasons."

 Citing "the threat from criminal groups and persons who engage in criminal enterprise that supports or contributes to terrorism," Loy listed as examples "people smuggling ... document forgery and false identity provision."

 Illegal aliens sneaking into the United States to commit terrorism need the same criminal services as illegal aliens sneaking into the United States to work. Mass illegal immigration -- and corporations that encourage it by hiring masses of illegal aliens -- have created an inland sea of lawlessness in which terrorist sharks can readily swim.

 In fact, on June 25, 2002, following an SSA examination of the identities used by the Sept. 11, 2001 hijackers, then-SSA Inspector General James G. Huse Jr. told the House Subcommittee on Crime that the hijackers used, among others, five counterfeit SSNs and one belonging to a child.

 "Because a terrorist, to be effective, must first be assimilated into American society, and because an SSN is a critical tool in the assimilation, it became apparent that the acquisition of an SSN was indispensable," said Huse.

 On Sept. 19, 2002, Huse told the House Immigration Subcommittee: "Protecting the integrity of that identifier (the Social Security Number) is as important to our homeland security as any border patrol or airport screening."

 Before Sept. 11, we had little warning. Now we've had plenty.

 To make terrorist sharks easier to spot and capture, the government must drain their habitat -- and it can start by pulling the plug on a policy that looks the other way when businesses hire illegal aliens.

 Huse told the Immigration Subcommittee: "Our reviews of the suspended wages in the ESF suggest that illegal work is the primary cause of suspended wages."

 If illegal work is the "primary cause" W-2s end up in the ESF, isn't it reasonable to suspect that companies filing large numbers of these W-2s may be hiring large numbers of illegal workers?

 House Judiciary Chairman James Sensenbrenner told me last month the Department of Homeland Security should investigate these companies to find out if that is the case.

 Make it happen, Mr. President.