Unitary, confederate and federal systems of government are three basic ways to organize the power in a country. In a unitary system, all power and sovereignty belong to the national government which, however, can transfer some of the powers to territorial units (and take it back at any time via legislative change). The same laws generally apply across all the country's regions. Most countries around the world are unitary. In a federation, the power and sovereignty are shared and balanced between the national (federal) government and territorial units (states). To change the states' powers or borders, it is usually necessary to amend the constitution. There are some national (federal) laws, which apply across all the country, while some laws differ across regions (states). In a confederation, power and sovereignty belong in principle to the smaller units (members), while the national (confederal) government is weak, has limited powers, and deals mostly with defense and foreign relations. Decisions are made by consensus of all members. Confederacy is a system of government for those who want to keep the power in each state and give only limited power to the national government.