The Evolution of Military Doctrine - Minimize civilian casualties not take out the cities

The principle of military necessity calls for using only that degree and kind of force required for the partial or complete submission of the enemy, while taking into consideration the minimum expenditure of time, life, and physical resources. This principle is designed to limit the application of force to that required for carrying out lawful military purposes. Although the principle of military necessity recognizes that some collateral damage and incidental injury to civilians may occur when a legitimate military target is attacked, it does not excuse the wanton destruction of lives and property disproportionate to the military advantage to be gained. For the employment of any weapon, the weapons used should not cause more destruction than necessary to achieve military objectives. Consequently, a conventional weapon may be all that is needed or a smaller yield nuclear weapon may be preferred over a larger yield warhead, if the military objectives can still be achieved.

In contrast, the principle of lawful targeting requires that all reasonable precautions be taken to ensure the targeting of only military objectives, so that damage to civilian objects (collateral damage) or death and injury to civilians (incidental injury ) is avoided as much as possible. This is often grouped under the term of “countervalue targeting”.[17]

Account for the deterrence asymmetry. A long-standing element of U.S. nuclear force planning has been that nuclear weapons are to hold at risk those assets and capabilities that an enemy values most. What is frequently left unstated in this planning is that an authoritarian or totalitarian enemy will have a different view of what is valuable compared with what the U.S. and its democratic allies value. These enemies view their means of strategic attack and internal repression as their most valuable assets. In contrast, the U.S. and its allies most value the well-being of their populations and their continued social and economic viability. This fundamental asymmetry in deterrence logically leads to the preference for both the protect and defend strategy and the counterforce targeting policy in the overall U.S. strategic posture. Any concept of deterrence that fails to account for this asymmetry will prove fragile and ultimately destabilizing.