LYMAN: He’s not the enemy. Scott, the Joint Chiefs, even the very emotional, very illogical lunatic fringe: they’re not the enemy. The enemy’s an age — a nuclear age. It happens to have killed man’s faith in his ability to influence what happens to him. And out of this comes a sickness, and out of sickness a frustration, a feeling of impotence, helplessness, weakness. And from this, this desperation, we look for a champion in red, white, and blue. Every now and then a man on a white horse rides by, and we appoint him to be our personal god for the duration. For some men it was a Senator McCarthy, for others it was a General Walker, and now it’s a General Scott.

Rod Serling (1924-1975) American screenwriter, playwright, television producer, narrator
Seven Days in May, film (1964)
    (Source)

Based on the 1962 novel by Fletcher Knebel and Charles W. Bailey II.

These lines are almost all Serling's. By wording, the only parallel I could find in the original novel was this:

The nuclear age, by killing man’s faith in his ability to influence what happens, could destroy the United States even if no bombs were ever dropped.
[Source]