Pakistani NATO oil tanker drivers, break their fast on top of the tankers, during the Muslim holy fasting month of Ramadan, in a compound in Karachi, Pakistan, Tuesday, July 31, 2012. Pakistan and the United States signed a deal regulating the shipment of American troops supplies to and from Afghanistan, prompting Washington to agree to release over $1 billion in frozen military aid. (AP Photo/Shakil Adil)