Question

The quote below was written by U.S. leader George Kennan: The quote below was written by U.S. leader George Kennan:

Now it lies in the nature of the mental world of the Soviet leaders, as well as in the character of their ideology, that no opposition to them can be officially recognized as having any merit or justification whatsoever. Such opposition can flow, in theory, only from the hostile and incorrigible forces of dying capitalism.
Source: History Guide

What does this quote justify?

Iron Curtain

Marshall Plan

U.S. foreign policy of containment

use of atomic weapons against the Soviet Union