 On 1 March , Clifford had succeeded McNamara as Secretary of Defense . During the month , Clifford , who had entered office as a staunch supporter of the Vietnam commitment and who had opposed McNamara 's de @-@ escalatory views , turned against the war . According to Clifford : " The simple truth was that the military failed to sustain a respectable argument for their position . " Between the results of Tet and the meetings of the group that bore his name , he became convinced that deescalation was the only solution for the United States . He believed that the troop increase would lead only to a more violent stalemate and sought out others in the administration to assist him in convincing the President to reverse the escalation , to cap force levels at 550 @,@ 000 men , to seek negotiations with Hanoi , and turn responsibility for the fighting over to the South Vietnamese . Clifford quietly sought allies and was assisted in his effort by the so @-@ called " 8 : 30 Group " – Nitze , Warnke , Phil G. Goulding ( Assistant Secretary of Defense for Public Affairs ) , George Elsey , and Air Force Colonel Robert E. Pursely . 
