As President Barack Obama prepares to welcome the sometimes controversial Pakistani Prime Minister Nawaz Sharif to the White House on Wednesday, U.S. officials are quietly preparing to release some $1.6 billion in aid for the south Asian nation that had been frozen ever since U.S. forces captured and killed 9/11 mastermind Osama bin Laden living in comfort not far from the Pakistani capital.

That raid -- which resulted in widespread anger in Pakistan against the U.S. and suspicion in the U.S. against Pakistan -- is just one of a number of thorny issues between the two ...