Afghan President Hamid Karzai, right, and Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, hold a meeting at the Presidential Palace in Kabul on December 14, 2009. Mullen, America's top military officer, expressed concern Monday about the 'growing level of collusion' between Taliban insurgents in Afghanistan and al-Qaida and other militant groups taking refuge across the border in Pakistan. UPI/Massoud Hossaini/POOL