Above all, the examples of Mexico and El Salvador show the difference that changing market conditions can make. More than 4,000 Salvadorans were saved by a spell of cooperation between their country’s maras, whereas some 60,000 Mexicans died because of an increase in competition among their country’s drug cartels. Neither outcome was inevitable. With stakes like that, governments should consider ways to shape these markets, rather than simply charge into battle to shut them down at any cost.
