Supranationalism is a method of decision-making in multi-national political communities, wherein power is transferred or delegated to an authority by governments of member states. The authority, subject to supranational democratic institutions and with a legal procedure can therefore institute a supranational rule of law above (supra) the constituent national legal order but subject to the same principles such as Human Rights and fundamental freedoms. This supranational legal order first saw light in the European Coal and Steel Community. The Council of Europe created a system based on Human Rights in its founding Statute and its Convention of Human Rights and Fundamental Freedoms. Robert Schuman, French Foreign minister, initiated the debate on supranational democracy in his speeches at the United Nations, at the signing of the Council's Statutes and at a series of other speeches across Europe and North America.

Because decisions in some supranational structures are taken by majority votes, it is possible for a member-state in those unions to be obliged by the other member-states to implement a decision. These decisions may include those that governments believe to be right but are reluctant to do so because of powerful, anti-democratic interests within their own country. This possibility arises because the States (through an internal democratic process) have earlier agreed to the process that some inter-State decisions in a specific sector should be subject to such democratic control.

The States retain the competence for adding this additional supranational competence. They also are responsible for it and the democratic legitimacy. (Kompetenz-Kompetenz). This includes referendums for the treaties implementing both supranational and other treaties. Supranational treaties by their nature require a higher degree of democratic assent.

Unlike states in a federal super-state, member states retain nominal sovereignty, although some sovereignty is shared with, or ceded to, the supranational body. Supranational agreements encourage stability and trust, because governments cannot break international accords at a whim. The supranational action may be time-limited. This was the case with the European Coal and Steel Community, which was agreed for 50 years with the possibility of renewal. Supranational accords may be permanent, such as an agreement to outlaw war between the partners. Full sovereignty can be reclaimed by withdrawing from the supranational arrangements but the member state would also lose the great advantages offered by mutualities, economies of scale, common external tariffs and other commonly agreed standards such as improved international trust and democracy and common external positions. The Council of Europe has suspended membership when States are taken over by dictatorships.

A supranational authority, by definition, can have some independence from member state governments in specific areas, although not as much independence as with a federal government. Supranational institutions, like federal governments, imply the possibility of pursuing agendas in ways that the delegating states did not initially envision. Democratic supranational Communities, however, are defined by treaty and by law. Their activity is controlled by a Court, democratic institutions and the rule of law.