By the end of the Nineteenth Century, public international law was essentially confined to the affairs of States; the direct involvement of individuals and corporations in matters of international law was marginal. International organizations of States or State agencies were in their infancy; the exemplar was the Universal Postal Union. The main engine of international law-making was customary international law, and it puffed along slowly, gradually accruing with the practice of States. Careers in international law were confined to a tiny band of advisers in the foreign ministries of the larger Powers and to the occasional professor of international law. It may be doubted whether there were a few hundred persons in all the world in 1899 who regarded themselves and were regarded as international lawyers.

By the end of the Twentieth Century, international law not only increasingly regulates the affairs of States, it has come to have a pervasive and continuing impact upon individuals, corporations, and non-governmental organizations. Public international organizations- the United Nations, its Specialized Agencies, regional international organizations ranging from the relatively integrated European Union (EU) to the Organization of American States (OAS) and the International Telecommunications Satellite Organization (INTELSAT)- have multiplied.

The main engine of international law-making has become the treaty. Today, thousands of treaties not only govern or endeavor to govern the great issues of war and peace- the United Nations Charter, the North Atlantic Treaty, the Geneva Conventions, and so on- but also unending aspects of the economic and social life of the peoples of the world. But for international law, aircraft would not fly across national boundaries; radio frequencies would go unallocated; satellite television and telephone calls would be impractical; epidemics would spread unhindered by cooperative medical action; international trade would be fundamentally constricted by national barriers; limits of jurisdiction in the seas would be anarchical; copyrights and trademarks would not be recognized abroad; and judgments of national courts and arbitral awards would be deprived of foreign recognition and enforcement.

The World Trade Organization (WTO), the World Bank and the International Monetary Fund (IMF) are creations of the treaty-making process; and they and other international organizations in turn contribute to the further development of international law. The United Nations itself, through its International Law Commission and the multilateral treaty-making conferences called in pursuance of its work, through the UN Commission on International Trade Law (UNCITRAL), and otherwise, has contributed immensely to the progressive development and codification of international law.

A result of this modern explosion of international law-making has been the transformation of the practice of international law. While at the turn of the 19^th Century, there were one or two solicitors in the Department of State, today considerably more than one hundred lawyers staff its Office of the Legal Adviser. The major international organizations- the United Nations, the International Labor Organization (ILO), the World Bank, IMF and some other of the Specialized Agencies- have substantial legal staffs, as do regional and specialized organizations such as the OAS and INTELSAT. International law is widely taught in the law faculties of the world and in many faculties of political science. Thousands of scholars work not in the field but in the fields of international law- some of which, such as human rights law and space law, are relatively recent phenomena- and private practitioners the world over find themselves concerned with problems of international law and transactions on a scale unknown until the last few decades of the Twentieth Century.

A student thinking today of a career in international law accordingly can consider more than one type of career. He or she may be interested in concentrating on the practice of public international law, in which case the likeliest fora are the offices of the legal adviser in foreign ministries and other ministries of international concern; in the United States, principally the State Department, Treasury Department, Departments of Defense and Commerce and the U.S. Trade Representative. The greatest office in the world for the practice of public international law is the Office of the Legal Adviser of the State Department. The range and interest of international legal problems with which a lawyer in that Office-- whether a beginner or a veteran- is daily confronted is unmatched; and the diplomatic, political, and economic elements of the daily grist are unbeatable. Careers in public international law can also be pursued in the larger international organizations, such as the United Nations, the World Bank, the IMF, the WTO, and the ILO.

A second and far larger stream of international legal practice is to be found in the private sector. For the most part, that practice- whether in law firms or in corporate law departments-- is concerned much more with private international transactions than public international law, though international law increasingly bears on elements of those transactions. The practitioner largely will deal with his or her national law and its interactions with foreign law and foreign clients, and the international flow of people and ideas and investments. Questions of international law may be encountered: questions of sovereign immunity, immigration, asylum, expropriation, the interpretation of treaties of commerce and navigation and of bilateral investment treaties, and so forth. A field of particular interest and rapid growth is that of international commercial arbitration. Very large numbers of international commercial disputes today are resolved not in the courts of one party or the other, but by international commercial arbitration of a tribunal often sitting in a third country under the chairmanship of a national of a country not involved. The resultant awards are recognized and enforced the world over in pursuance of one of the many treaties that significantly affect the practice of law the world over, the United Nations (New York) Convention on the Recognition and Enforcement of Foreign Arbitral Awards.

There is the old saying that those who can do; those who can’t teach. A third career in international law is the academic. Many of the most distinguished international lawyers of the Twentieth Century have been professors of international law, who have made great contributions not only to the theory, but also to the practice of international law. There are few fields in the law that offer more scope for the creativity of the individual than international law. There are few fields in the law that offer more of a challenge to the individual of idealism and commitment than international law.

Practice before the International Court of Justice draws mainly from the offices of the legal advisers of the litigant States. Since only States may be parties to contentious cases before the Court, and only public international organizations may request advisory opinions, it is natural that most of the lawyers who plead before the Court come from the legal offices of those States and international organizations. But those offices often reach out to faculties of law and to the bar for support. There is no "World Court Bar" but there is a band of international lawyers who recurrently argue before the Court who are retained by a variety of States because of their eminence as international lawyers and because of their experience in the Court.

* Judge and Vice President, International Court of Justice.

Published with permission from Careers in International Law by the American Society of International Law, Washington, D.C. This publication, which includes many other essays on a variety of practices in international law, is available in the NYLS Law Library's first floor reference area JX 1291.I58 1996 Ref.