According to the President`s historian Robert Dallek, Kissinger`s advice « was not based on a particular knowledge of decision-making in the White House, but on an intelligent view of what was going on. » CIA intelligence analyst William Bundy said Kissinger had received « no useful inside information » from his trip to Paris and that « almost all experienced observers in Hanoi were able to come to the same conclusion. » While Kissinger « may have hinted that his advice was based on contacts with the Paris delegation », this kind of « self-promotion… In the worst case, it is a minor and non-unusual practice, which is very different from having real secrets and reporting them.  According to Finnish historian Jussi Hanhimki, southern Vietnam was put under pressure because of the triangular diplomacy that isolated it to accept an agreement that virtually ensured its collapse.  During the negotiations, Kissinger stated that 18 months after an agreement, the United States would not intervene militarily, but that it could intervene before. In the history of the Vietnam War, this has been described as a « decent interval. »  Nixon asked the eminent Asian-American politician Anna Chennault to be his « channel to Mr. Thieu »; Chennault agreed and regularly reported to John Mitchell that Thieu had no intention of attending a peace conference. On November 2, Chennault told the South Vietnamese ambassador: « I just heard from my boss in Albuquerque, who says his boss [Nixon] is going to win. And you`ll tell your boss [Thieu] to hold on for a while longer.  Johnson learned about the NSA and was furious that Nixon had « blood on his hands » and that Senate Minority Leader Everett Dirksen agreed with Johnson that such an action was a « betrayal. »    Defence Minister Clark Clifford considered this to be an unlawful violation of the Logan Act.  In response, President Johnson ordered the listening of members of the Nixon campaign.   Dallek wrote that Nixon`s efforts « probably made no difference » because Thieu was unwilling to participate in the talks and there was little chance of reaching an agreement before the elections; However, his use of the information provided by Harlow and Kissinger was morally questionable and Vice President Hubert Humphrey`s decision not to make Nixon`s actions public is « an unusual act of political decency. »  Nixon then told the President of South Vietnam, Nguyen Van Thieu, that he had to make peace, whether he agreed or not, and that he was therefore obliged to sign. However, as American casualties increased throughout the conflict since 1965, American support for the war deteriorated and in the fall of 1972 the Nixon administration came under intense pressure to withdraw from the war.