State formation worldwide has always involved significant attention to infrastructural and fiscal integration across the state territory. This process is often referred to as national integration. Its absence and/or the exacerbation of disparities between localities and provinces can lead to calls for secession or autonomy, particularly when allied to concentrations of populations with cultural or ethnic differences from the national majority. Historically, localities, regions, and established states have sometimes come together to create federal or similar arrangements in which lower‐order units share governmental powers with higher‐order ones. The creation of such geographical blocs when it involves pre‐existing nation‐states is often referred to as regional integration. Today the best examples of such integration are so‐called supranational regional unions, such as the European Union, and much less institutionalized trading blocs, such as NAFTA.