clay pan: see hardpan.

Pan-Slavism, theory and movement intended to promote the political or cultural unity of all Slavs. Advocated by various individuals from the 17th cent., it developed as an intellectual and cultural movement in the 19th cent. It was stimulated by the rise of romanticism and nationalism, and it grew with the awakening of the Slavs within the Austrian and Ottoman empires. Slavic historians, philologists, and anthropologists, influenced by Johann Gottfried von Herder, helped spread a national consciousness among the Slavs, and some dreamed of a unified Slavic culture to replace an allegedly declining Latin-German culture. The first Pan-Slav Congress, held at Prague in 1848 and presided over by František Palacký, was confined to the Slavs under Austrian rule and was anti-Russian. The humiliating defeat suffered by Russia in the Crimean War (1853-56) helped transform a vague, romantic Russian Slavophilism into a militant and nationalistic Russian Pan-Slavism. Prominent among the Russian Pan-Slav publicists were Rotislav Andreyevich Fadeyev and Nikolai Yakovlevich Danilevsky. Fadeyev claimed that it was Russia's mission to liberate the Slavs from Austrian and Ottoman domination by war and to form a Russian-dominated Slavic federation. Danilevsky predicted a long conflict between Russia and the rest of Europe, to be followed by a federation of states including the Greeks, Magyars, and Romanians as well as the Slavs. In the reign of Czar Alexander II, the foreign minister, Aleksandr Gorchakov, opposed Pan-Slav aspirations, although many officials were Pan-Slavist. Pressures from the Pan-Slavs probably helped provoke the Russo-Turkish War of 1877-78 but afterward declined. In the decade preceding World War I, Pan-Slav agitation again increased and played a role in the growing conflict between Russia and Austria in the Balkan peninsula, where the Serbs opposed Austria. In 1908, Russia was forced to allow Austrian annexation of Bosnia and Herzegovina, but in 1914 Russia supported Serbia in the crisis that began World War I. After the Bolsheviks triumphed in the Russian Revolution of 1917, the Soviet government renounced Pan-Slavism. In World War II, however, Pan-Slavist slogans were revived to facilitate Slavic and Communist dominance of Eastern European countries. Both in the 19th and 20th cent. Pan-Slav aspirations were limited by the conflicting political and economic hopes of the various groups of Slavs.

Pan-Germanism, German nationalist doctrine aiming at the union of all German-speaking peoples under German rule. Pan-Germanists considered that not only the German groups in neighboring countries, such as Austria, Czechoslovakia, Poland, Switzerland, and Alsace, but even distant German-speaking groups such as Volga Germans, Baltic Germans, Transylvanian Germans, and German-Americans were linked by a blood tie to their fatherland. The doctrine originated in the late 19th cent. as an instrument of German imperialistic expansion. In 1893 the Alldeutscher Verbund (Pan-German League) was founded. The Pan-Germans became particularly vocal after Germany's defeat in World War I had deprived it of some border territories and its colonies. National Socialism appropriated Pan-Germanism; by the annexation of Austria and of German-speaking parts of Czechoslovakia in 1938 and by German conquests in Europe during World War II, Adolf Hitler nearly succeeded for a time in making the Pan-German program a reality.

Pan-Arabism, general term for the modern movement for political unification among the Arab nations of the Middle East. Since the Ottoman Turks rose to power in the 14th cent., there have been stirrings among Arabs for reunification as a means of reestablishing Arab political power. At the start of World War I, France and Great Britain, seeking allies against the German-Turkish alliance, encouraged the cause of Arab nationalism under the leadership of the Hashemite Sherif Husayn ibn Ali, a descendant of Muhammad. As ruler of Mecca and a religious leader of Islam, he had great influence in the Arab world, an influence that continued with his two sons, Abdullah and Faisal (Faisal I of Iraq). From the 1930s, hostility toward Zionist aims in Palestine was a major rallying point for Arab nationalists.

The movement found official expression after World War II in the Arab League and in such unification attempts as the Arab Federation (1958) of Iraq and Jordan, the United Arab Republic, the Arab Union (1958), the United Arab Emirates, and the Arab Maghreb Union (see under Maghreb). The principal instrument of Pan-Arabism in the early 1960s was the Ba'ath party, which was active in most Arab states, notably Egypt, Iraq, Jordan, Lebanon, Saudi Arabia, Syria, and Yemen. Gamal Abdal Nasser of Egypt, who was not a Ba'athist, expressed similar ideals of Arab unity and socialism.

The defeat of the Arabs in the Arab-Israeli War of 1967 and the death (1970) of Nasser set back the cause of Pan-Arabism. In the early 1970s, a projected merger between Egypt and Libya came to nought. However, during and following the 1973 Arab-Israeli War, the Arab states showed new cohesion in their use of oil as a major economic and political weapon in international affairs. This cohesion was fractured by the signing of the Camp David accords between Egypt and Israel and by the Iran-Iraq War. Pan-Arabist rhetoric was used by Iraqi President Saddam Hussein in an attempt to stir opposition the UN coalition forces during the Persian Gulf War, but many Arab nations joined the anti-Iraq coalition.

Pan-Americanism, movement toward commercial, social, economic, military, and political cooperation among the nations of North, Central, and South America.

In the Nineteenth Century

The struggle for independence after 1810 among the Latin American nations evoked a sense of unity, especially in South America where, under Simón Bolívar in the north and José de San Martín in the south, there were cooperative efforts. Francisco Morazán briefly headed a Central American Federation. The United States was looked upon as a model, and recognition of the new republics was a part of U.S. foreign policy. Henry Clay and Thomas Jefferson set forth the principles of Pan-Americanism in the early 1800s, and soon afterward the United States declared through the Monroe Doctrine a new policy with regard to interference by European nations in the affairs of the Western Hemisphere. Initially welcomed, despite establishing U.S. hegemony, the doctrine later was seen by many Latin American nations as a mask for U.S. imperialistic ambitions.

In the 19th cent., Latin American military nationalism came to the fore. Venezuela and Ecuador withdrew (1830) from Greater Colombia; the Central American Federation collapsed (1838); Argentina and Brazil fought continually over Uruguay, and then all three combined in the War of the Triple Alliance (1865-70) to defeat Paraguay; and in the War of the Pacific (1879-83), Chile defeated Peru and Bolivia. However, during this same period Pan-Americanism existed in the form of a series of Inter-American Conferences—Panama (1826), Lima (1847), Santiago (1856), and Lima (1864). The main object of those meetings was to provide for a common defense. The first of the modern Pan-American Conferences was held (1889-90) in Washington, D.C., with all nations represented except the Dominican Republic. Treaties for arbitration of disputes and adjustment of tariffs were adopted, and the Commercial Bureau of the American Republics, which became the Pan-American Union, was established. Subsequent meetings were held in various Latin American cities.

In the Twentieth Century

In the early 20th cent., U.S. manipulation to secure the Panama Canal and its intervention in the affairs of other Latin American states, combined to create Latin American resentment toward the United States. There was progress, however, in the codification of international law, acceptance of peace machinery, and creation of scientific and social agencies. Troubles nonetheless continued to flare. A major war was fought (1932-35) between Bolivia and Paraguay over the Chaco (see Gran Chaco). Strained relations between the United States and Panama were temporarily resolved by a treaty signed in 1936. Although it still restricted Panama's sovereignty, it ended the American right of intervention.

With the administration of Franklin Delano Roosevelt a policy of determined cordiality toward Latin America—the "Good Neighbor" policy—bore fruit. As World War II approached, the nations of the Western Hemisphere drew closer together. Conferences held in 1936 and 1938 provided for consultation in case of outside threat. Accordingly, after the outbreak of World War II the Inter-American Neutrality Conference was held (1939) in Panama. A conference of foreign ministers at Havana produced (1940) the Act of Havana, declaring against changes of sovereignty in the Western Hemisphere. Most of the Latin American nations (with the notable exception of Argentina) supported or actually joined the Allies after the Japanese attack on Pearl Harbor.

A significant step was taken at the Inter-American Conference on the Problems of War and Peace in Mexico City in 1945. The Act of Chapultepec, adopted there by 20 republics, called for joint action in repelling aggression against an American state, including that by another American state. Acceptance by Argentina established machinery to enforce peace in the Western Hemisphere. This was formalized by the Inter-American Treaty of Reciprocal Assistance (the Rio Treaty). In other fields, too, cooperation advanced, as in commercial and financial matters (e.g., the Inter-American Bank). As a consequence of the growing awareness of interdependence the Bogotá Conference of 1948 produced the Organization of American States (OAS) to promote hemispheric unity. In the late 1950s the United States took steps toward an international price agreement on agricultural products and minerals, a measure long advocated by Latin American republics plagued by one-product economies. The Inter-American Development Bank began operations early in 1960.

Since the 1960s one of the most persistent issues facing the inter-American system has been the Communist government in Cuba and the strong opposition to it in the United States. Fidel Castro's support for Communist guerrilla forces in other Latin American countries led, in 1962, to Cuba's expulsion from the OAS. The vote, however, was not unanimous; Argentina, Bolivia, Brazil, Chile, Ecuador, and Mexico abstained. Nonetheless, in the same year Latin American nations backed the United States in its blockade of Cuba following the construction of missile bases there. By the 1990s, however, almost all Latin American countries had resumed trade and diplomatic relations with Cuba. In 1989, in yet another clash with Panama, the United States invaded to remove its de facto leader, Manuel Noriega, and to establish an elected government, despite the OAS's calls for U.S. withdrawal.

With the introduction of the Alliance for Progress in 1961, the United States undertook a long-term plan of economic assistance. In partial recognition of the weakness of this program, the Declaration of the Presidents of America was signed (1967) in Punta del Este, Uruguay, expressing commitment to Latin American economic integration, i.e., the creation of a common market (see Central American Common Market; Latin American Integration Association). Although economic cooperation has not proceeded as quickly as originally planned, there has been progress toward the lowering of trade barriers in both North and South America, especially with the creation of Mercosur in 1991 and the North American Free Trade Agreement (NAFTA) in 1992. These developments kept alive hopes for ultimate inter-American economic integration, and in Apr., 2001, 34 Western Hemisphere nations committed themselves to the creation of a Free Trade Area of the Americas, but negotiations toward its creation subsequently stalled.

Pan-American games, amateur athletic competition among representatives of countries in the Western Hemisphere. The competition, held every four years, follows the organization and eligibility rules of the Olympic games and is held in the year before the Olympics in different host cities. World War II delayed the first Pan-American games, originally planned for 1942, but not held until 1951. There were 19 events in the 1951 games, but a full schedule of Olympic sports now comprises the program. The United States has usually dominated the events.

Pan-American Union, former name for the General Secretariat of the Organization of American States (OAS). It was founded (1889-90) at the first of the modern Inter-American Conferences (see Pan-Americanism) as the Commercial Bureau of the American Republics and changed to the International Bureau of the American Republics in 1902. The name Pan-American Union was adopted in 1910. Created to promote international cooperation, it offered technical and informational services to all the American republics, served as the repository for international documents, and was responsible through subsidiary councils for the furtherance of economic, social, juridical, and cultural relations. In 1948 it was made the General Secretariat for the OAS, although the name was not dropped until 1970. The anniversary of its founding is Pan-American Day.

Pan-American Highway, system of roads, c.16,000 mi (25,750 km) long, linking the nations of the Western Hemisphere. It was suggested at the Fifth International Conference of American States (1923) and supported and financed by the United States during the 1940s and 1950s. Gaps are in Panama (Darién Gap) and N Colombia, in the section called the Inter-American Highway. The route from Yaviza (Panama) to Colombia is surveyed but not constructed. The section between the United States and the Panama Canal is popular with tourists driving to Mexico. Climatic zones along the highway vary from lush jungle to cold mountain passes nearly 15,000 ft (4,572 m) high. The scenery is often spectacular, and the highway crosses many picturesque localities. The system is far from uniform; some stretches are passable only during the dry season, and in several regions driving is occasionally hazardous. In the late 1960s, much of the highway was improved.

Pan-American Health Organization, inter-American health organization. It was established in 1902 as the International Sanitary Bureau; the present name was adopted in 1958. Its members include all the Latin American nations, Canada, and the United States. France, Great Britain, and the Netherlands are also associated with the organization on behalf of their departments and territories in the Western Hemisphere. The organization cooperates with members in developing public services, collects health statistics, and aids in the control of communicable diseases.

Pan-Africanism, general term for various movements in Africa that have as their common goal the unity of Africans and the elimination of colonialism and white supremacy from the continent. However, on the scope and meaning of Pan-Africanism, including such matters as leadership, political orientation, and national as opposed to regional interests, they are widely, often bitterly, divided.

One catalyst for the rapid and widespread development of Pan-Africanism was the colonization of the continent by European powers in the late 19th cent. The First Pan-African Congress, convened in London in 1900, was followed by others in Paris (1919), London and Brussels (1921), London and Lisbon (1923), and New York City (1927). These congresses, organized chiefly by W. E. B. Du Bois and attended by the North American and West Indian black intelligentsia, did not propose immediate African independence; they favored gradual self-government and interracialism. In 1944, several African organizations in London joined to form the Pan-African Federation, which for the first time demanded African autonomy and independence. The Federation convened (1945) in Manchester the Sixth Pan-African Congress, which included such future political figures as Jomo Kenyatta from Kenya, Kwame Nkrumah from the Gold Coast, S. L. Akintola from Nigeria, Wallace Johnson from Sierra Leone, and Ralph Armattoe from Togo. While at the Manchester congress, Nkrumah founded the West African National Secretariat to promote a so-called United States of Africa.

Pan-Africanism as an intergovernmental movement was launched in 1958 with the First Conference of Independent African States in Accra, Ghana. Ghana and Liberia were the only sub-Saharan countries represented; the remainder were Arab and Muslim. Thereafter, as independence was achieved by more African states, other interpretations of Pan-Africanism emerged, including: the Union of African States (1960), the African States of the Casablanca Charter (1961), the African and Malagasy Union (1961), the Organization of Inter-African and Malagasy States (1962), and the African-Malagasy-Mauritius Common Organization (1964).

In 1963 the Organization of African Unity (OAU) was founded to promote unity and cooperation among all African states and to bring an end to colonialism; it had 53 members by 1995. The OAU struggled with border disputes, aggression or subversion against one member by another, separatist movements, and the collapse of order in member states. One of its longest commitments and greatest victories was the end of apartheid and the establishment of majority rule in South Africa. Efforts to promote even greater African economic, social, and political integration led to the establishment in 2001 of the African Union (AU), a successor organization to the OAU modeled on the European Union. The AU fully superseded the OAU in 2002, after a transitional period.

Pan, in astronomy, one of the named moons, or natural satellites, of Saturn. Also known as Saturn XVIII (or S18), Pan is 12.5 mi (20 km) in diameter, orbits Saturn at a mean distance of 83,000 mi (133,583 km), and has an orbital period of 0.575 earth days. The rotational period is unknown but is assumed to be the same as the orbital period. It was discovered by Mark R. Showalter at the Ames Research Center in California in 1990 while reviewing photographs taken by Voyager 1 during its flyby of Saturn in 1980. The innermost of Saturn's confirmed moons, Pan's orbit is within the Encke Division, or Encke Gap, of Saturn's A ring, where it functions as a shepherd satellite (a moon that limits the extent of a planetary ring through gravitational forces), keeping the gap open.

Pan, in Greek religion and mythology, pastoral god of fertility. He was worshiped principally in Arcadia, and one legend states that he was the son of Hermes, another Arcadian god. Pan was supposed to make flocks fertile; when he did not, his image was flogged to stimulate him. He was depicted as a merry, ugly man with the horns, ears, and legs of a goat. Occasionally ill-tempered, he loved to frighten unwary travelers (hence the word panic). All his myths deal with amorous affairs. In a famous tale he pursued the nymph Syrinx, but before she was overtaken her sister nymphs changed her into a reed. Thus Pan plays the reed, or syrinx, in memory of her. Later, when Pan was worshiped in other parts of Greece and in Rome, he became associated with the Greek Dionysus and identified with the Roman Faunus, both gods of fertility.

Fan Si Pan, peak, 10,312 ft (3,143 m) high, on the divide between the Red and Black rivers, NW Vietnam, near the Chinese border. It is the highest point in Vietnam.

or pan or flat or dry lake

Flat-bottomed depression that is periodically covered by water. Playas occur in interior desert basins and adjacent to coasts in arid and semiarid regions. The water that periodically covers the playa slowly filters into the groundwater system or evaporates into the atmosphere, causing the deposition of salt, sand, and mud along the bottom and around the edges of the depression.

Learn more about playa with a free trial on Britannica.com.

Movement to unite Slav peoples of eastern and central Europe. It began in the early 19th century when Slav intellectuals studied their common cultures. Political goals for Slavic unity increased in 1848, when a Slav congress organized by Frantishacekek Palacký met in Prague to press for equal rights under Austrian rule. In the 1860s the movement became popular in Russia, to which Pan-Slavs looked for protection from Turkish and Austro-Hungarian rule; this led Russia and Serbia into wars against the Ottoman Empire in 1876–77. In the 20th century, nationalist rivalries among the Slav peoples prevented their effective collaboration.

Learn more about Pan-Slavism with a free trial on Britannica.com.

Movement to politically unify all German-speaking people. The desire for German unification began in the early 19th century and was advanced by Ernst Arndt and other early nationalists. The Pan-German League was organized in 1894 by Ernst Hasse (1846–1908) to heighten German nationalist awareness, especially among German-speaking people outside Germany. The movement, which pressed for German expansion in Europe, gained support after World War I under the Weimar Republic and was actively promoted by Adolf Hitler and the Nazi Party. After Germany's defeat in 1945 and the expulsion of Germans from formerly German areas of eastern Europe, the movement declined.

Learn more about Pan-Germanism with a free trial on Britannica.com.

International highway system connecting North and South America. Conceived in 1923 as a single route, the road grew to include a number of designated highways in participating countries, including the Inter-American Highway from Nuevo Laredo, Mex., to Panama City, Pan. The whole system, extending from Alaska and Canada to Chile, Argentina, and Brazil, totals nearly 30,000 mi (48,000 km). Only some 240 miles (400 km) in the Panama-Colombia border area remain uncompleted.

Learn more about Pan-American Highway with a free trial on Britannica.com.

Greek fertility deity with a half-human, half-animal form. The Romans associated him with Faunus. Pan was usually said to be the son of Hermes. He was often represented as a vigorous and lustful figure with the horns, legs, and ears of a goat; in later art his human parts were more emphasized. Some Christian depictions of the Devil bear a striking resemblance to Pan. Pan haunted the high hills, where he was chiefly concerned with flocks and herds. Like a shepherd, Pan was a piper, and he rested at noon. He could inspire irrational terror in humans, and the word panic comes from his name.

Learn more about Pan with a free trial on Britannica.com.