The democratic transition that occurred in many parts of the world in the late 20th century resulted in the proliferation of courts charged with constitutional adjudication, though the formal powers of these high courts vary considerably from one country to another. Some are specialized courts of constitutional review, usually called the constitutional court or constitutional tribunal (e.g., Spain, Portugal, Italy, Germany, and Greece); others blend the functions of judicial review of legislation and cassation, or the review of lower-court decisions (e.g., Ireland, the United States, Denmark); and still others exercise only the power of cassation (France [see Cour de Cassation], Belgium, Luxembourg, and the United Kingdom). Some countries have multiple high courts with various functions and powers. Italy, for example, has a Constitutional Court with the sole power to exercise constitutional review and a Supreme Court of Cassation with the power to review the decisions of ordinary courts for consistency with the law. Egypt also maintains a Court of Cassation that monitors the uniformity of lower-court fidelity to the law, but only its Supreme Constitutional Court has the authority to declare laws unconstitutional and to determine and rule upon legislative intent. In Japan the Supreme Court is the only court explicitly permitted to exercise judicial review. Its authority is limited to cases involving conflicting parties and therefore does not entertain questions brought by government officials. The role orientation of the Japanese judge and judicial system is conflict resolution; as such, the courts are reluctant to exercise judicial review or engage in judicial activism. In most systems, the power to strike down acts of the national legislature is centralized in a specialized tribunal; in a small number of countries, including Portugal and the United States, it is decentralized, or “diffused,” with every court empowered to exercise judicial review over legislation.

The precise circumstances under which a national high court can exercise the power of judicial review also vary considerably. Some courts, exercising what is called “concrete” judicial review (incidenter, or a review incidental to deciding a case), can strike down legislation only in a particular case. Other courts are empowered to engage in “abstract” judicial review (the review of a law on constitutional grounds without application to a particular pending case). Of the courts with the power of abstract review, some can exercise it prior to a statute’s taking effect (i.e., a priori review), while others exercise it only after the law has taken effect (a posteriori review). Many of the architects of the constitutions of the democracies that emerged in the 1990s in central and eastern Europe opted for a strong, centralized form of judicial power, with the power of judicial review residing in a constitutional tribunal, typically with the power to engage in both abstract and concrete review. Constitutional courts in France and Germany may exercise abstract judicial review. Arguably, Portugal’s constitutional tribunal has the greatest jurisdiction, exercising both concrete review of lower-court decisions and abstract review of all laws and legal norms. The U.S. Supreme Court avoids advisory opinions and therefore does not engage in abstract judicial review.

Courts in federal systems

Many countries, such as the United Kingdom, France, and Japan, have unitary judicial systems in which all courts (i.e., regular courts as distinguished from administrative bodies) fit into a single national hierarchy of tribunals along the lines just described. Other countries, organized on a federal basis, tend to have more complicated court structures, reflecting the fragmentation of governmental powers between the central authority and local authorities. In the United States, for example, there are 51 separate judicial systems, one for each state and another for the federal government. To a limited extent, the jurisdiction of the federal courts is exclusive of that exercised by the state courts, but there are large areas of overlap and duplication. Unless state laws or state constitutions conflict with national laws or the national constitution, state courts are the final arbiters of the meaning of state law. At the top level is the Supreme Court of the United States, which hears appeals not only from the lower federal courts but also from state courts insofar as they present federal questions arising under the Constitution of the United States or under federal statutes or treaties. If a case in a state court involves only a question of state law—for example, the interpretation of a state statute—the ultimate authority is the state supreme court, and no appeal is possible to the U.S. Supreme Court.

Court structure in a federal form of government need not be as complicated as that in the United States. It is possible to have only one set of courts for the country, operated by the central government and handling all cases that arise under state law as well as federal law. Germany is also a federal republic, dividing power between the federal and state systems. At the national level, there are five supreme courts and one constitutional court. The supreme courts represent separate jurisdictions (civil and criminal, general administrative, employment and trade-union disputes, social policy, and financial matters and taxation).

Another possibility is for each state or province to have its own system of courts, handling all questions of federal as well as state law, and for the central government to maintain only a single supreme court to decide questions as to the relationship of the central authority and the local authorities or as to the relationship between the local authorities themselves. This pattern is found in Canada and Australia.

Another complication resulting from a federal form of government is that questions involving conflict of laws arise with great frequency. Such questions concern the choice to be made between the law of one jurisdiction and that of another as the rule for a decision in a particular case. Even in a unitary system, such problems cannot be avoided; for example, a court in the United Kingdom may be called upon to try a case arising from a transaction that took place in France and to decide whether British or French law should govern. Such problems arise much more often, however, in federal systems, where laws differ from state to state and people move about very freely. Their activities in one state sometimes become the subject of a lawsuit in another, and the court is required to decide which law should apply.

Transnational courts

Although courts with jurisdictions that traverse national boundaries have been in existence for quite some time (e.g., the International Court of Justice [ICJ] was established in 1945, replacing an international court that was created after World War I), generally they have been too weak to warrant much attention. More recently, however, transnational courts such as the European Court of Justice (the high court of the EU) and the European Court of Human Rights have become quite powerful, and the ICJ has garnered an enhanced reputation. These courts generally enforce treaty obligations and related interstate agreements.

The European Court of Justice is sometimes credited with having created a variety of new individual rights for citizens of the EU, often superseding national laws (e.g., rights to gender equality). Indeed, the European Court of Justice has been successful in declaring the laws of the EU to be superior to national laws and thereby undermining the long-established principles of parliamentary sovereignty (as in the United Kingdom). Many observers believe that no single institution has been more instrumental in creating a united Europe than the European Court of Justice.

The International Criminal Court (ICC), which began sittings in 2002, represents a specialized type of transnational court devoted to prosecuting criminal activity. Created in part in response to the war crimes committed in the former Yugoslavia and Rwanda in the 1990s (separate international tribunals were established to prosecute allegations of war crimes in each conflict), the ICC was empowered to try individuals accused of war crimes, genocide, and crimes against humanity. Because of the nonparticipation of several major countries (e.g., China, Russia, and the United States), however, many observers questioned whether the ICC could effectively prosecute and deter such crimes.