By Monday, October 15, 6:38 PM A month after the assault on the U.S. mission in Benghazi, a fateful series of television appearances by Susan E. Rice, the American ambassador to the United Nations, is haunting the Obama administration in the face of allegations that it deliberately attempted to play down suspicions of terrorist involvement. Rice made the rounds of the Sunday morning talk shows on Sept. 16, five days after the attack in the Libyan city, and in each one she said the fatal assault appeared to have stemmed from a spontaneous protest over an anti-Islam video.