President Barack Obama gave the go-ahead for U.S. forces to raid a northern Pakistan housing compound based on "what was probably a 50-50 chance that Osama bin Laden was there," his national security adviser said. "At the end of last year, we assessed that al Qaeda had been diminished ... to its weakest since 2001," said the security adviser... On April 28, Obama attended the last of several National Security Council meetings focused on finding and going after the al Qaeda leader. During that meeting, some advocated for the commando raid while others advised against it, Donilon said, given there...