Narrow channels of marginal sea or inland waters through which international shipping has a right of passage.
In international law, international waterways are straits, canals, and rivers that connect two areas of the high seas or enable ocean shipping to reach interior ports on international seas, gulfs, or lakes that otherwise would be land-locked. International waterways also may be rivers that serve as international boundaries or traverse successively two or more states. Ships have a right of passage through international waterways. This right is based on customary international law and treaty arrangements.
Some straits are more important than others because they are the sole connecting links between oceans and interior waters. For example, the Strait of Gibraltar gives access from the Atlantic Ocean to the Mediterranean and Aegean Seas. Other straits are not as important. The availability of alternate routes does not in itself deprive a strait of its character as an international waterway. In the Corfu Channel case, 1949 I.C.J. 4, 1949 WL 1 (I.C.J.), the international court of justice rejected the test of essentiality as the only route, ruling that "the decisive criterion is rather [the strait's] geographic situation as connecting two parts of the high seas and the fact of its being used for international navigation."
The 1958 geneva convention on the Territorial Sea and Contiguous Zone (516 U.N.T.S. 205, 15 U.S.T. 1606, T.I.A.S. No. 5639) does not deal comprehensively with international waterways, but does provide that "[t]here shall be no suspension of innocent passage of foreign ships through straits which are used for international navigation between one part of the high seas and another part of the high seas or the territorial sea of a foreign state" (art. 16, § 4). A territorial sea is the water that comes under the sovereign control of a state.
A coastal state has somewhat greater control of innocent passage through its territorial seas than of innocent passage through a strait joining two areas of high seas. Passage may be suspended through territorial waters when essential for security. This means that warships are free to pass through straits but may be denied access to territorial seas.
Since the 1960s a great majority of coastal states have extended their claims on territorial seas from three miles to 12 miles from the low-water mark, some even farther. This change has been a matter of concern to the U.S. government, as a 12-mile limit converts 121 straits to territorial seas, some of which have strategic military importance.
With respect to international marine traffic, canals joining areas of the high seas or waters leading to them are geographically in the same position as straits. However, the significant canals have been constructed in accordance with international treaties or later placed under conventional legal regimes. The Suez Canal, located in Egypt, and the Panama Canal are the two most important canals in international commerce.
The United States played the major role in the construction of the Panama Canal, which joins the Atlantic and Pacific Oceans across the Isthmus of Panama. The canal is over 40 miles long and has a minimum width of three hundred feet.
In 1903, after several European-financed efforts to build a canal across the isthmus had failed, the U.S. government negotiated the Hay-Bunau-Varilla Treaty (T.S. No. 431, 33 Stat. 2234, 10 Bevans 663). Under this treaty the United States guaranteed the independence of Panama (which had just broken away from Colombia) and secured a perpetual lease on a ten-mile strip for the canal. Panama was to receive an initial payment of $10 million and an annuity of $250,000, beginning in 1913.
In 1906, President theodore roosevelt directed construction of the canal to begin under the supervision of the U.S. Army Corps of Engineers. The Panama Canal was completed in 1914 and officially opened by President woodrow wilson on July 12, 1920.
The Hay-Bunau-Varilla Treaty stated that the canal was to be neutralized and free and open to vessels of commerce and war on terms of equality, and without discrimination as to tolls or conditions of passage. However, it did not mandate open access in times of war. The United States decided, in 1917, to close the canal and the territorial waters of the canal zone (the ten-mile-wide strip of land that contained the canal) to vessels of enemy states and their allies whenever the United States is a belligerent. This was done in World Wars I and II.
From the 1920s to the 1970s, the United States and Panama had many disputes concerning control of the Panama Canal Zone. Panamanians came to regard the zone as part of their country and believed that the 1903 treaty was unfairly favorable to the United States. In 1971, the two countries began negotiations for a new treaty to replace the 1903 agreement.
In 1977, Panama and the United States concluded the Treaty Governing the Permanent Neutrality and Operation of the Panama Canal, and the Panama Canal Treaty (both Washington, D.C., 1977, in force 1979; Digest of United States Practice in International Law, 1978, at 1028–560). The treaties provided that the United States would relinquish control and administration of the canal to Panama by December 31, 1999, and stipulated an interim period for the training of, and progressive transfer of functions to, Panamanian personnel under the supervision of a mixed Panama Canal Commission.
The first treaty declared that the canal would be permanently neutralized (as would any other international waterway later constructed wholly or partly in Panamanian territory), with the object of securing it for peaceful transit in time of peace or of war for vessels of all nations on equal terms (arts. 1, 2). The right of passage
extends not only to merchant ships but to vessels of war and auxiliary vessels in noncommercial service of all nations "at all times," irrespective of their internal operations, means of propulsion, origin, destination, or armament (art. 3, § 1[e]).
In early December 1999, a United States delegation, headed by former U.S. president jimmy carter (who signed the original treaty in 1977), attended the official transfer of the canal into Panamanian hands. Other attendees included Spain's King Juan Carlos, and the presidents of Bolivia, Columbia, Ecuador, and Mexico. As of 2000, it was estimated that approximately 1,400 ships pass through the canal annually.
Customary international law has never granted equal access and rights to countries that share navigable rivers either as boundaries between them or as waterways that traverse them successively. Freer use of international rivers has occurred in the nineteenth and twentieth centuries through the negotiation of treaties.
The St. Lawrence Seaway, opened for navigation by large ships in 1959, is an example of a legal and an administrative regime wholly devised and controlled by the two states (the United States and Canada) that share it. Based on a river in part, the seaway was developed with the construction of bypass canals, locks, and channel improvements, sometimes wholly within the territory of one state. In 1909, canada and the united states consolidated and extended a number of earlier piecemeal arrangements in the Boundary Waters Treaty (36 Stat. 2448, 12 Bevans 359), to give both nations equal liberty of navigation in the St. Lawrence River, the Great Lakes, and the canals and waterways connecting the lakes. An international boundary line was drawn generally along the median line of the lakes (with some variation in Lake Michigan), but both nations were to exercise concurrent admiralty and criminal jurisdiction over the whole of the lakes and their connecting waterways. The admiralty jurisdiction reflected a disposition to treat the lakes as the high seas. This view was supported by the U.S. Supreme Court in United States v. Rodgers, 150 U.S. 249, 14 S. Ct. 109, 37 L. Ed. 1071 (1893), when it referred to the "high seas of the lakes."
The building of the St. Lawrence Seaway was complicated by the failure of Canada and the United States to negotiate an agreement for the creation of a joint international authority to supervise the project. Instead, each country established its own national agency to construct the canals, locks, and other works required for the 27-foot channel, making each agency responsible for work on its own side of the river. The agencies coordinated their work in a series of international agreements and informal arrangements. Where works extended over the international boundary, the two commissions allocated responsibility through the coordination of work at the technical level. They agreed on uniform rules of navigation, coordination of pilotage services, uniform tolls, and arrangements for collection.
Seagoing merchant vessels from other countries use the seaway regularly. Their right to do so rests not on any general principle of free navigation, but on national agreements and Article V of the general agreement on tariffs and trade, which mandates freedom of transit for merchant ships through the territories of signatories for traffic to or from the territory of other signatories. As the Great Lakes are inland waters and have been demilitarized since the Rush-Bagot Agreement of 1817 (T.S. No. 110½, 2 Miller 645, 12 Bevans 54), it is unlikely that foreign warships will request or receive permission to visit their ports.
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