The first meaning war as a tool can be derived from Carl von Clausewitzs understanding of war as a political and rational phenomenon. A second understanding of war implies that war means intense violence or mass killings. The relationship between conflict, killing and war, therefore, may not be as clear in Clausewitzs thought as it is sometimes portrayed. Military historian Azar Gat suggests that Clausewitzs premature death from cholera before he could finish revising on War has led to a fierce debate over the last two centuries regarding interpretations. Guerrilla warfare is hardly a new phenomenon and it is therefore difficult to squeeze it in as a development logically following from a certain state of interstate war. Moreover, while old wars were fought by large-scale, organized, uniformed armed forces in pitch battles, new wars are characterized by a deliberate attack on civilians by rag-tag groups of warlords, criminals, militias, and rebel fractions, not centrally or hierarchically led and commanded.