The recent publication of the Iraq Study Group report has drawn parallels with the famous conclave of "wise men" to advise President Lyndon Johnson on his Vietnam policy around the time of the 1968 Tet offensive.
Johnson had been making use of a circle of non-administration foreign policy advisors for some time. A "Vietnam Panel" met on 8 July 1965 and offered an assessment of future policy. The most famous such meeting was held under state department auspices in November 1967 (document 377). However, at a subsequent meeting in March 1968 (document 142), it appears as if Johnson has lost confidence in the "wise men" approach. It's not clear if the comment referring to it being "a mistake to get a new super-Presidential board" should be attributed to him or to Dean Acheson (or maybe both). Twelve days later, Johnson made his dramatic announcement that he would not seek re-election.