The International Court of Justice was established in 1945 by the UN Charter as the principal judicial organ of the United Nations. It is based in the Peace Palace in the Hague, the Netherlands. Its main functions are to settle legal disputes submitted to it by states and to give advisory opinions on legal questions submitted to it by duly authorized international organs, agencies, and the UN General Assembly.
The ICJ is composed of 15 judges elected to 9 year terms by the UN General Assembly and the UN Security and may be re-elected for up to two further terms. No two may be nationals of the same country. All judges should be "elected regardless of their nationality among persons of high moral character", who are either qualified for the highest judicial office in their home states or known as lawyers with sufficient competence in international law. Decisions and Advisory Opinions are by majority and, in the event of an equal division; the President's vote becomes decisive. Generally, the Court sits as full bench, but it is allowed under the statute to form smaller chambers, usually 3 or 5 judges, to hear cases. Members of the Court are independent judges and they exercise their powers impartially and conscientiously.
As stated in the UN Charter, all 192 UN members are automatically parties to the Court's statute. The issue of jurisdiction is considered in the two types of ICJ cases: contentious issues and advisory opinions.
In contentious cases (adversarial proceedings seeking to settle a dispute), the ICJ produces a binding ruling between states that agree to submit to the ruling of the court. Only states may be parties in contentious cases. The key principle is that the ICJ has jurisdiction only on the basis of consent.
An advisory opinion is a function of the Court open only to specified United Nations bodies and agencies. Advisory Opinions were intended as a means by which UN agencies could seek the Court's help in deciding complex legal issues that might fall under their respective mandates.
The duty of all UN members is to comply with decisions of the Court involving them. If one of the parties fails to heed a judgment of the ICJ the other party may call upon the Security Council to determine measures to be taken against it.
When deciding cases, the Court applies international law i.e international conventions, international custom, and the "general principles of law recognized by civilized nations". If the parties agree, they may also grant the Court the liberty to decide ex aequo et bono ("in justice and fairness"), granting the ICJ the freedom to make an equitable decision based on what is fair under the circumstances.
Court procedure is set out in Rules of Court of the International Court of Justice. Cases before the ICJ will follow a standard pattern. The case is lodged by the applicant who files a written memorial setting out the basis of the Court's jurisdiction and the merits of its claim. The respondent may accept the Court's jurisdiction and file its own memorial on the merits of the case. Once all written arguments are filed, the Court will hold a public hearing on the merits.