The nation that will insist upon drawing a broad line of distinction between the fighting man and the thinking man is liable to find its fighting done by fools and its thinking by cowards.
-- Sir William Francis Butler
Cyberspace, where information―and hence serious value―is stored and manipulated, is a tempting target. An attacker could be a person, group, or state and may disrupt or corrupt the systems from which cyberspace is built. When states are involved, it is tempting to compare fights to warfare, but there are important differences. The author addresses these differences and ways the United States protect itself in the face of attack.