North Atlantic Treaty Organization (NATO), established under the North Atlantic Treaty (Apr. 4, 1949) by Belgium, Canada, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, and the United States. Greece and Turkey entered the alliance in 1952, West Germany (now Germany) entered in 1955, and Spain joined in 1982. In 1999 the Czech Republic, Hungary, and Poland joined, and Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia joined five years later, bringing the membership to 26. NATO maintains headquarters in Brussels, Belgium.

The treaty, one of the major Western countermeasures against the threat of aggression by the Soviet Union during the cold war, was aimed at safeguarding the freedom of the North Atlantic community. Considering an armed attack on any member an attack against all, the treaty provided for collective self-defense in accordance with Article 51 of the United Nations Charter. The treaty was also designed to encourage political, economic, and social cooperation. The organization was reorganized and centralized in 1952, and has undergone subsequent reorganizations.

NATO's highest organ, the North Atlantic Council, may meet on several levels—heads of government, ministers, or permanent representatives. The council determines policy and supervises the civilian and military agencies; NATO's secretary-general chairs the council. Under the council is the Military Committee, which may meet at the chiefs of staff or permanent representative level. Its headquarters in Washington, D.C., has representatives of the chiefs of staff of all member countries; France, however, withdrew from the Military Committee from 1966 to 1995 while remaining a member of the council.

NATO is now divided into two commands. Allied Command Operations is headed by the Supreme Allied Commander Europe (SACEUR). SACEUR directs NATO forces and, in time of war, controls all land, sea, and air operations. Allied Command Transformation, with headquarters at Norfolk, Va., is responsible for making recommendations on the strategic transformation of NATO forces in the post-cold-war era.

In the 1990s, with the collapse of the Soviet Union and the Warsaw Treaty Organization, NATO's role in world affairs changed, and U.S. forces in Europe were gradually reduced. Many East European nations sought NATO membership as a counterbalance to Russian power, but they, along with other European and Asian nations (including Russia), initially were offered only membership in the more limited Partnership for Peace, formed in 1994. Twenty-three countries now belong to the partnership, which engages in joint military exercises with NATO. NATO is not required to defend Partnership for Peace nations from attack. In 2002, NATO and Russia established the NATO-Russia Council, through which Russia participates in NATO discussions on many nondefense issues.

NATO has increasingly concentrated on extending security and stability throughout Europe, and on peacekeeping efforts in Europe and elsewhere. NATO air forces were used under UN auspices in punitive attacks on Serb forces in Bosnia in 1994 and 1995, and the alliance's forces were subsequently used for peacekeeping operations in Bosnia. NATO again launched air attacks in Mar.-June, 1999, this time on the former Yugoslavia following following the breakdown of negotiations over Kosovo. In June, 1999, NATO was authorized by the United Nations to begin trying to restore order in the province, and NATO peacekeeping forces entered Kosovo. In Aug., 2003, NATO assumed command of the international security force in the Kabul area in Afghanistan, which by 2006 had expanded to include some 31,000 troops (including 11,000 Americans) deployed throughout Afghanistan; and in Oct., 2003, a NATO rapid-response force was established.

The membership of many NATO nations in the increasingly integrated European Union (EU) has led to tensions within NATO between the United States and those EU nations, particularly France and Germany, who want to develop an EU defense force, which necessarily would not include non-EU members of NATO. In 2008 NATO extended invitations to join to Albania and Croatia; disagreements between Greece and Macedonia over the latter's name led Greece to veto an invitation to Macedonia. Georgia and Ukraine were promised eventual membership but not given any timetable; Russia had objected strongly to their becoming NATO members.

North Atlantic Drift, warm ocean current in the northern part of the Atlantic Ocean. It is a continuation of the Gulf Stream, the merging point being at lat. 40°N and long. 60°W. Off the British Isles it splits into two branches, one going south (the Canary Current) and the other going north along the coast of W and N Europe, where it exerts considerable influence upon the climate as far as northwestern Europe.

Mid-Atlantic Ridge: see Atlantic Ocean.

Atlantic cable: see cable.

Atlantic Provinces, term used since 1949 to designate the Canadian provinces of Newfoundland and Labrador, Nova Scotia, New Brunswick, and Prince Edward Island.

Atlantic Ocean [Lat.,=of Atlas], second largest ocean (c.31,800,000 sq mi/82,362,000 sq km; c.36,000,000 sq mi/93,240,000 sq km with marginal seas).

Physical Geography

Extent and Seas

The Atlantic Ocean extends in an S shape from the arctic to the antarctic regions between North and South America on the west and Europe and Africa on the east. It is connected with the Arctic Ocean by the Greenland Sea and Smith Sound; with the Pacific Ocean by Drake Passage, the Straits of Magellan, and the Panama Canal; and with the Indian Ocean by the Suez Canal and the expanse between Africa and Antarctica. The shortest distance across the Atlantic Ocean (c.1,600 mi/2,575 km) is between SW Senegal, W Africa, and NE Brazil, E South America. The principal arms of the Atlantic Ocean are Hudson and Baffin bays, the Gulf of Mexico, and the Caribbean Sea in the west; the Baltic, North, Mediterranean, and Black seas in the east; and the Weddell Sea in the south. More large rivers, including the Mississippi, the Congo, and the Amazon, drain into the Atlantic than into any other ocean.

Islands

The Atlantic has relatively few islands, with the greatest concentration found in the Caribbean region. Most of the islands are structurally part of the continents, such as the British Isles, Falkland Islands, Canary Islands, and Newfoundland. Iceland, the Azores, the islands of Cape Verde, Ascension, the South Sandwich Islands, the West Indies, and Bermuda are exposed tops of submarine ridges. The Bahamas are low coral islands that sit on the Blake Plateau, while the Madeiras are high volcanic islands.

Ocean Floor

The floor of the Atlantic has an average depth of c.12,000 ft (3,660 m). It is separated from that of the Arctic Ocean by a submarine ridge extending from SE Greenland to N Scotland; part of the floor (c.3,000 ft/910 m deep) is known as "telegraph plateau" because of the network of cables laid there. A shallow submarine ridge across the Strait of Gibraltar separates the Mediterranean basin from the Atlantic and limits the exchange of water between the two bodies. The Mid-Atlantic Ridge (c.300-600 mi/480-970 km wide), a submarine mountain range extending c.10,000 mi (16,100 km) from Iceland to near the Antarctic Circle, generally follows the trend of the coastlines of the continents. It rises to an average height of c.10,000 ft (3,050 m), and a few peaks emerge as islands. The ridge, which is the center of volcanic activity and earthquakes, has a great rift that is constantly widening (see seafloor spreading) and filling with molten rock from the earth's interior. As a result the Western Hemisphere and Europe and Africa are moving away from each other. The Mid-Atlantic Ridge divides the floor of the Atlantic Ocean into eastern and western sections that are composed of a series of deep-sea basins (abyssal plains). The greatest depth (c.28,000 ft/8,530 m) is the Milwaukee Deep, in the Puerto Rico Trench, N of Puerto Rico. Scientific knowledge of the ocean floor dates from the Challenger expedition (1872-76).

Currents

Because of its shape, the Atlantic may be divided into two basins—North Atlantic Ocean and South Atlantic Ocean—each with a distinct circulation system. The clockwise-moving currents of the North Atlantic (North Equatorial Current, Antilles Current, Gulf Stream, North Atlantic Drift, Canaries Current) and the counterclockwise-moving currents of the South Atlantic (South Equatorial Current, Brazil Current, West Wind Drift, Benguela Current) are separated from each other by the Equatorial Counter Current; the Guinea Current off W Africa is a link between the two systems. At the Grand Banks off Newfoundland heavy fogs form along the front where the warm Gulf Stream meets the cold Labrador Current. The surface waters in the Atlantic's trade wind belts attain the highest salinity known in ocean water.

Commerce and Shipping

The North Atlantic Ocean has some of the world's busiest shipping lanes; the northern lanes are patrolled for icebergs. Commerce between the Mediterranean Sea and the NE Atlantic Ocean was initiated by the Carthaginians. From the 7th cent. A.D., Scandinavians navigated the Atlantic; they probably reached North America c.1000. Trade routes along the coast of Africa were opened by Portugal in the 15th cent. and to the Western Hemisphere by Spain after the voyages of Columbus. The Grand Banks have traditionally contained some of the world's best commercial fishing grounds, but by the early 1990s the area had been overfished, and many species were depleted.

Atlantic City, city (1990 pop. 37,986), Atlantic co., SE N.J., an Atlantic resort and convention center; settled c.1790, inc. 1854. Situated on Absecon Island, a barrier island 10 mi (16.1 km) long, Atlantic City was a fishing village until the construction in 1854 of a railroad that made it a fashionable resort for Philadelphians and New Yorkers. The first boardwalk was built in 1870. Atlantic City's chief industry is tourism, with more than 30 million visitors annually. The casino industry, which was legalized in 1976 and began in 1978, rivals that in Las Vegas, Nevada. The boardwalk, lined with casinos, hotels, shops, and amusements, is 6 mi (9.7 km) long. Urban blight, however, has continued to contrast sharply with oceanfront prosperity. Atlantic City has a large convention center. The Democratic national convention took place in the city in 1964, and the Miss America Pageant was held there annually from 1921 to 2005. Absecon Lighthouse, in operation 1854-1932, attracts tourists. The first Ferris wheel was built in Atlantic City in 1869. The board game Monopoly, which makes use of area street names, was invented here in 1930.

Atlantic Charter, joint program of peace aims, enunciated by Prime Minister Winston Churchill of Great Britain and President Franklin Delano Roosevelt of the United States on Aug. 14, 1941. Britain at that time was engaged in World War II, and the United States was to enter the war four months later. The statement, which was not an official document, was drawn up at sea, off the coast of Newfoundland. It supported the following principles and aims: renunciation of territorial aggrandizement; opposition to territorial changes made against the wishes of the people concerned; restoration of sovereign rights and self-government to those forcibly deprived of them; access to raw materials for all nations of the world and easing of trade restrictions; world cooperation to secure improved economic and social conditions for all; freedom from fear and want; freedom of the seas; and abandonment of the use of force, as well as disarmament of aggressor nations. In the United Nations declaration of Jan. 1, 1942, the signatory powers pledged adherence to the principles of the charter.

in full North Atlantic Treaty Organization

International military alliance created to defend western Europe against a possible Soviet invasion. A 1948 collective-defense alliance between Britain, France, The Netherlands, Belgium, and Luxembourg was recognized as inadequate to deter Soviet aggression, and in 1949 the U.S. and Canada agreed to join their European allies in an enlarged alliance. A centralized administrative structure was set up, and three major commands were established, focused on Europe, the Atlantic, and the English Channel (disbanded in 1994). The admission of West Germany in 1955 led to the Soviet Union's creation of the opposing Warsaw Treaty Organization, or Warsaw Pact. France withdrew from military participation in 1966. Since NATO ground forces were smaller than those of the Warsaw Pact, the balance of power was maintained by superior weaponry, including intermediate-range nuclear weapons. After the Warsaw Pact's dissolution and the end of the Cold War in 1991, NATO withdrew its nuclear weapons and attempted to transform its mission. It involved itself in the Balkan conflicts of the 1990s. Article 5 of the North Atlantic Treaty stated that an attack on one signatory would be regarded as an attack on the rest. This article was first invoked in 2001 in response to the terrorist September 11 attacks against the U.S. Additional countries joined NATO in 1999 and 2004 to bring the number of full members to 26. In 2009 France announced its plan to rejoin NATO's integrated military command.

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Submarine ridge lying along the floor of the central Atlantic Ocean. It is a long mountain chain running about 10,000 mi (16,000 km) in a general but curving north-south direction from the Arctic Ocean to the southern tip of Africa. The mountains sometimes reach above sea level, forming such islands or island groups as Ascension, the Azores, St. Helena, and Tristan da Cunha.

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Ocean separating North and South America from Europe and Africa. The second largest of the world's oceans, the Atlantic has an area of 31,830,000 sq mi (82,440,000 sq km). With its marginal seas, including the Baltic, North, Black, and Mediterranean to the east, and Baffin Bay, Hudson Bay, the Gulf of St. Lawrence, Gulf of Mexico, and Caribbean Sea to the west, it covers some 41,100,000 sq mi (106,450,000 sq km). Including these latter bodies of water, its average depth is 10,925 ft (3,330 m); its maximum depth is 27,493 feet (8,380 m) in the Puerto Rico Trench. Its most powerful current is the Gulf Stream.

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City (pop., 2000: 40,517) and resort, southeastern New Jersey, U.S. Lying on narrow Absecon Island, the resort began to be developed in the mid-19th century. Amusement piers were constructed, and the first beachfront boardwalk was built there in 1870. The Miss America Pageant was established in Atlantic City in 1921. After World War II the city began to decline. In 1976 the state approved legalized gambling, and extensive development in Atlantic City provided a huge influx of money to the resort, but much of the surrounding area remained impoverished.

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Joint declaration issued on Aug. 14, 1941, during World War II, by Winston Churchill and Franklin D. Roosevelt. Among the statements made in this propaganda manifesto, signed when the U.S. had not yet entered the war, were that neither the U.S. nor Britain sought aggrandizement and that both advocated the restoration of self-government to peoples forcibly deprived of it. The charter was incorporated by reference in the Declaration of the UN (1942).

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