The principle of critical mass is so simple that it is no wonder that it shows up in epidemiology, fashion, survival and extinction of species, language systems, racial integration, jaywalking, panic behavior, and political movements.

Because people vary and because averages matter, there may be no sustainable critical mass; and the unravelling behavior, or initial failure to get the activity going at all, has much the appearance of a critical mass that is almost but not quite achieved. This is therefore a kindred but separate family of models.

This is a difference between nuclear weapons and bayonets. It is not in the number of people they can eventually kill but in the speed with which it can be done, in the centralization of decision, in the divorce of the war from political processes, and in computerized programs that threaten to take the war out of human hands once it begins.

If a model meets the criterion of simplicity it will often, like the thermostat-controlled heating system, describe physical and mechanical systems as well as social phenomena, animal behavior as well as human, scientific principles as well as household activities. An example is “critical mass.

Nuclear weapons can do it quickly. That makes a difference.

I define game theory as the study of how rational individuals make choices when the better choice among two possibilities, or the best choice among several possibilities, depends on the choices that others will make or are making.

Earlier wars, like World Wars I and II or the Franco-Prussian War, were limited by termination, by an ending that occurred before the period of greatest potential violence, by negotiation that brought the threat of pain and privation to bear but often precluded the massive exercise of civilian violence. With nuclear weapons available, the restraint of violence cannot await the outcome of a contest of military strength; restraint, to occur at all, must occur during war itself. This.

The generic name for behaviors of this sort is critical mass. Social scientists have adopted the term from nuclear engineering, where it is common currency in connection with atomic bombs.

Models tend to be useful when they are simultaneously simple enough to fit a variety of behaviors and complex enough to fit behaviors that need the help of an explanatory model.

Military strategy... has become the diplomacy of violence.