Dr. Walid Phares: Terrorist-linked immigrants have been crossing southern border for years

National Security Advisor Dr. Walid Phares says the San Diego U.S. Customs and Border Protection’s memo warning of possible attempts by Hamas fighters to cross the southern border only confirms what security analysts have known for a while. Dr. Phares explains how illegal immigrants linked to terrorist organizations and the Iranian regime have been strategically crossing the southern border for years.