All trade involves networks of nodes (centers) and linkages (usually transport routes). Types of nodes include places where commodities or raw materials originate, where they are processed or manufactured, where they are received and shipped to other destinations, or where they are bought for consumption. Land, air, and water transportation systems provide linkages between these nodes. These nodes and linkages can be seen in the illegal drug trade, as shown in the map in the activity. Some nodes are production areas for growing the crops that provide the raw material for drugs. These are linked to other areas that process the crops to produce the drugs. The final destination is the market, where the drugs are consumed. All these areas are connected by air, land, and sea transportation routesthe red arrows on the mapeither directly or through transit hubs, which are centers that both receive and distribute goods. For example, the opium poppy is grown in Southeast Asia, where it is also processed into heroin. The drug is then sent to markets in North America and Europe. Financing is also essential to global trade. As the map shows, some nodes, such as Bangkok and New York City, act as major