While decisionmakers warn about the cyber threat constantly, there is little systematic analysis of the issue from an international security studies perspective. Some scholars presume that the related technology’s scientific complexity and methodological issues prohibit orderly investigation; only a minimum degree of technical acuity is needed, however, revealing the scope of maneuver in the cyber domain. Other skeptics argue that the cyber peril is overblown, contending that cyber weapons have no intrinsic capacity for violence and do not alter the nature or means of war. This view misses the essence of the danger and conceals its true significance: the new capability is expanding the range of possible harm and outcomes between the concepts of war and peace—with important implications for national and international security. The cyber domain, moreover, features enormous defense complications and dangers to strategic stability: offense dominance, attribution difficulties, technological volatility, poor strategic depth, escalatory ambiguity, and proliferation to nontraditional and subversive actors. But even if the cyber danger is overstated, the issue merits serious scholarly attention. Whatever the current cyber revolution signifies, it is detrimental to the intellectual progress and policy relevance of the field to continue to avoid its central questions.