Based upon information provided by the National Security Agency, which broken the South Vietnamese diplomatic codes, senior officials Johnson administration had learned that Anna Chennault, the chairwoman of the Republican Women for Nixon group had met the South Vietnamese ambassador, Bui Diem, to tell him that South Vietnam should sabotage Paris peace talks to improve the chances of Nixon winning the election. On 29 October 1968, Rostow told Johnson he now had information "on how certain Republicans may have inflamed the South Vietnamese to behave as they have been behaving". Rostow also advised Johnson not to go public with this information, saying he should instead tell Nixon in private to keep away from Chennault, advice which was taken. By the fall of 1968, Rostow had come to feel that it was better if Nixon won the election rather than the "defeatist" Humphrey who on the campaign trail had become increasingly critical of the war. In one of his memos to Johnson, Rostow, who was still unhappy about Johnson's decision not to invade North Vietnam, wrote he should say if asked about civilian-military relations: "Generally speaking, the military has wanted us to use more power, earlier and faster. They may have been right. But the president had other considerations to think of". It was a mark of Rostow's influence that Johnson, who was well known for being abrasive towards subordinates, did not explode in rage as he would have if anyone else wrote such a memo.