This article investigates Karl Barth's ethics of war and its reception by placing the discussion within the larger framework of the general ethics of Church Dogmatics II/2 and the special ethics of Church Dogmatics III/4. It gives careful attention to the infamously problematic “exceptional case” to illumine what sort of “exception,” if any, the provocative passages on war entail. The outlines of Barth's ethical framework and the Grenzfall, or borderline case, provide the background for the re‐evaluation of three common interpretations of his views on war.