Integration is important in politics, business, and technology. In all these fields, the definition of integration is vague. We build a formal measure of integration based on the latency of communication, and show how it can be used to optimize a courier assignment problem. Through simulation, we show how networks grow as couriers are added. Our measure captures the tradeoff between locality and expansion, as well as providing a model for triangle closure. Finally, we form conjectures about political integration which can be tested through empirical research.