The international regimes has increased greatly over the past few decades in an expanding breadth of areas, including global trade and finance, international security, human rights, the environment, transportation and communications and the Internet. Advances in transportation and communications technology increase the potential for international migration around the world. As international migration becomes less inhibited by physical or economic constraints and more of a function of legal constraints imposed by states, it turns into an increasingly important issue in politics among states. A regime governing intra-EU migration was first articulated in the Treaty of Rome, reaffirmed in the Single European Act (SEA) and formally codified in the European Citizenship provisions of the Treaty on European Union (TEU) signed at Maastricht. During the 1990s, policy-makers from the major migration destination countries such as United States, Germany, Canada, Australia, the UK, France, Italy and Austria became increasingly concerned with the smuggling of migrants across their borders.