The Security Council is the most powerful body in the UN. It is responsible for maintaining international peace, and for restoring peace when conflicts arise. Its decisions are binding on all UN members. The Security Council has the power to define what is a threat to security, to determine how the UN should respond, and to enforce its decisions by ordering UN members to take certain actions. The Council convenes(召集)any time there is a threat to peace. A representative from each member country who sits on the Council must be available at all times so that the Council can meet at a moment's notice. The Security Council also frequently meets at the request of a UN member—often a nation with a grievance (委屈，冤情) about another nation's actions. The Security Council has 15 members, five of which hold permanent seats. The Assembly elects the other ten members for two-year terms. The five permanent members — the United States, Britain, France, Russia (formerly the Soviet Union), and China have the most power. These nations were the winning powers at the end of World War II, and they still represent the bulk of the world's military might. Decisions of the Council require nine votes. But any one of the permanent members can veto an important decision. This authority is known as the veto right of the great powers. As a result, the Council is effective only when its permanent members can reach a consensus(一致同意). The Council has a variety of ways it can try to resolve conflicts among countries. Usually the Council's first step is to encourage the countries to settle their disagreements without violence. The Council can mediate (仲裁，调停) a dispute or recommend guidelines for a settlement. It can send peacekeeping troops into a distressed area. If a war breaks out, the Council can call for a ceasefire. It can enforce its decisions by imposing economic sanctions on a country, or through joint military action. Which of the following statements is TRUE according to the passage?