WASHINGTON (AP) - President Barack Obama's top national security adviser Tom Donilon is resigning and will be replaced by Susan Rice, the U.S. ambassador to the U.N. who has been a lightning rod for Republican criticism over faulty explanations for the attack that killed four Americans in Benghazi, Libya. Donilon has been a key foreign policy adviser to President Barack Obama. But the 58-year-old had been expected to depart sometime this year, with Rice seen as the likely candidate to replace him. Her selection is sure to anger congressional Republicans, who have accused the administration of inconsistency and a cover-up...