WASHINGTON, Nov. 26 (UPI) -- Law enforcement documents have revealed security measures at Fort Huachuca in Arizona were changed after warnings of a possible terror attack. The documents said an estimated 60 Afghan and Iraqi terrorists were planning with the help of Mexican drug cartels to sneak into the United States through underground tunnels and attack the base, the largest intelligence-training center in the country, with high-powered weapons, The Washington Times reported Monday. "A portion of the operatives were in the United States, with the remainder not yet in the United States," said one of the documents, a Federal Bureau...