Al Qaeda's second-in-command on Friday accused the United States of leading a crusade to turn Pakistan into a divided nation and urged Pakistanis to join in a jihad to resist. The tape from Ayman al-Zawahri, the second this month, comes after Pakistani Taliban chief Baitullah Mehsud was killed in a U.S. missile strike on Aug. 5. It also comes after Pakistan's army went on the offensive in late April against an insurgency by al Qaeda allies, the Taliban, in Swat valley after the militants took over the district 120 km (80 miles) from Islamabad, raising fears for Pakistan's stability and...