 McNamara told the journalists "No amount of bombing can end the war".Karnow, one of the journalists present during the "off-the-record" conversation, described McNamara's personality as having changed, noting the Defense Secretary who was normally so arrogant and self-assured, convinced he could "scientifically" solve any problem, as being subdued and clearly less self-confident.In October 1966, McNamara returned from yet another visit to South Vietnam, full of confidence in public and doubt in private.