Every war has its own preparations, both for its deterrence and for its actual conduct. Each type of war embodies a 'level of violence' or 'violence quotient' particular to itself. The 'violence quotient' is expressed in the weapons employed: conventional, tactical, nuclear, or strategic nuclear. Preparedness for each type of war constitutes in itself deterrence for that type of war. Deterrence including different types of forces is called mixed deterrence. Preparedness which includes the capacity to fight both nuclear and conventional wars has been termed dual preparedness. The rule of maintaining dual preparedness has become a cardinal tenet and a principal cornerstone of strategy. Upon examination, the two 'clusters' of strategic approaches and doctrines appear to embody a deep dilemma inherent to nuclear strategy. 'Finality of deterrence' and the strategic doctrines associated with it are based on the assumption that increasing the violence of the deterrent threat will decrease the chances of war.