In his Karl Barth and the Problem of War, and Other Essays on Barth , Yoder examines places where Barth’s views on pacifism and war conflict with Barth’s insights in other areas of theology. Yoder gives us a Barthian critique of Barth.

One crucial point concerns natural revelation: “The point at which Barth is most completely ‘non-Barthian’ is the point at which, when we ask him what it means for God to speak here and now, he presents us not with the Word of God spoken to the situation, but with the bare situation. Barth has told the pacifists that they are sinning against God’s freedom by denying to God the possibility that he might command war. The pacifists can answer that if God command Karl Barth to go to war he should certainly obey, but what they have not yet seen is that this was truly a command of God. When the reader looks for the identification of God’s commandment, Barth brings forth in the last analysis not a word which was spoken through him as if by a prophet in the Old Testament sense, not a mystical intuition or conscientious conviction of divine leading, not a clear ethical value judgment, not a revelatory vision or audition, not an interpretation of Scripture, but simply a political situation in which he saw nothing else for Switzerland to do.”

Barth’s vigorous Nein! to natural revelation, and to liberal theology’s use of natural revelation especially, left him without a theological ground for claiming that a historical situation might constitute a command of God. Yoder says elsewhere that the just war tradition rests on appeals to natural law in the sense of “the way the world works”; but this criticism of Barth shows a deeper sense in which just war theory depends on an affirmation of natural revelation.