We need now to make a structural change in our way of thinking about U.S.-Soviet relations. Our habit since World War II has been to move back and forth between) simplified extremes—to vacillate between overly sanguine expectations in which the inevitable difficulties in relations with the USSR are minimized and overly pessimistic and emotional positions in which the elements of change in the relationship are neglected. It is hard for public opinion in this country, perhaps in any country, to face up to emotionally unsatisfying ambiguities.