[4] After the Tet Offensive in early 1968, Warnke led an effort by civilian leaders in the Pentagon to educate the new Secretary of Defense, Clark Clifford, about the difficult military situation and the need to consider peace negotiations.
[5] While serving as the General Legal Counsel of the Secretary of Defense, he expressed doubt as to Israel’s explanation of the 1967 USS Liberty incident: “I found it hard to believe that it was, in fact, an honest mistake on the part of the Israeli air force units.
I suspect that in the heat of battle they figured that the presence of this American ship was inimical to their interests, and that somebody without authorization attacked it.”[6][7] Under President Jimmy Carter he was chief SALT negotiator and Director of the Arms Control and Disarmament Agency.
"[8] Unlike many of his critics, most famously Paul Nitze, Warnke didn't believe in the late 1970s that the Soviets had a desire to attack the United States or that they would succeed if they did.
During this period he served as an adviser to presidential candidate George McGovern and also wrote a noteworthy article in Foreign Policy magazine, "Apes on a Treadmill".
That piece criticized the current buildup of nuclear weapons by both sides and suggested that the United States unilaterally stop developing the B-1 bomber and the Trident submarine for six months.