I disagree with the above description of a Nash equilibrium. My understanding of such a thing is: When a Nash equilibrium exists each player's best strategy to the others create a "equilibrium" point, or a point from which you don't deviate. In a sense a change in government creates a change in game, not necessarily a Nash EQ. A Nash EQ in a society with a generally "Capitalist" economic, with supporting legal statutes, potentially result in players robbing, stealing, or cheating. However, in a game in which "Communism" is the economic standard, a Nash EQ may be universal altruism or chaos (my hypothesis to two possible Nash EQ's --not based in observation).Thus it is incorrect to blanketly label "Communism" or "Socialism" as a Nash EQ. In a sense a Nash EQ doesn't care about the morality of its players behaviors only that it is a relative equilibrium which results in best strategies that do not deviate in play.
See this Yale open course: http://oyc.yale.edu/economics/game-theory/.