Responding to the critiques of the four previous authors, Walzer opens with a statement of the inherent imperfection of any theory of war. He reminds us that theories are merely frameworks for decisions and cannot provide answers in and of themselves. Moral decisions in war are especially difficult, for it is often necessary to choose between equally valid claims. Walzer continues the discussion of sieges initiated by both Koontz and Boyle and concedes the validity of Koontz's criticism of inconsistency in his theory of noncombatant immunity. Addressing the different authors' moral doctrines–Hendrickson's consequentialism and Koontz's and Boyle's deontology–Walzer argues that it is better to judge each case individually, weighing both the consequences and principles, rather than strictly adhere to one moral doctrine, an approach commended by Smith. Finally, in the search for a perfect just war theory, Walzer issues a realist reminder that there can be no such thing as a morally perfect war.