In Egypt, President Nasser attempted to improve agricultural productivity through the construction
of the Aswan Dam. Although the project provided additional farmland, its interference in the normal
flood patterns of the Nile River deprived the land of the fertile silt deposited by the Nile’s flooding.
Also, parasites that caused blindness appeared in greater numbers, and increased deposits of salt were
found in the soil.
Migration Patterns
After World War I, the population of Latin America swelled as immigrants continued to pour into
Argentina and Brazil as well as into other Latin American countries. Urban areas grew rapidly. Latin
America experienced sizable migration within the continent as the inhabitants of rural areas migrated
to urban regions in search of employment. Newcomers often were forced to live in shantytowns on
the outskirts of urban areas. Sometimes these settlements were incorporated into urban areas,
resulting in somewhat improved living conditions within the former shantytowns.
In the 1920s, workers from Mexico crossed into the United States at the same time that Central
Americans were crossing into Mexico in search of employment. During the 1940s, the United States
set up programs with Mexico to provide workers. Hundreds of thousands of migrants, both legal and
illegal, continued to cross the border into the United States. Throughout Latin America, migration in
search of employment occurred across national borders. Other migrants reached, or attempted to
reach, the United States to escape political oppression and warfare. This last group included
immigrants from Cuba, Haiti, Nicaragua, and El Salvador.
Population flight from countries undergoing ethnic or religious strife or alterations in political
boundaries remained an issue in the period since 1914. The largest displacement of people in history
occurred in South Asia in 1947 and 1948, when the partition of India and Pakistan produced a major
migration of Muslims to Pakistan and Hindus to India. The first Arab-Israeli War in 1948 created
hundreds of thousands of Palestinian Arab refugees. In 1998, in the Balkan region of Kosovo,
thousands of ethnic Albanians of the Muslim faith fled the region in the face of Serbian massacres.
From 2000 to 2004, religious conflict in Nigeria caused Christians and Muslims to flee to areas
where their religion was the majority faith. In the Sudan, inhabitants of the southern region of the
country, most of them Christians or practitioners of native religions, were displaced from their
homes when Sunni Arabs from the northern regions of Sudan attempted to impose Islamic law upon
the southern regions. By 2004, the Sudanese conflict focused on the region of Darfur and involved a
conflict between Arab and non-Arab Muslims.
Another pattern of migration involved the movement of South Asians and Arabs toward the oil-
producing regions of the Middle East. Also, workers from developed nations including the United
States sought employment with their own nation’s companies in the oil fields of the Middle East.
Environmental Concerns
The world faced a number of environmental issues: damage to marine life from oil spills, the danger
of meltdowns from nuclear plants, and the devastation of warfare. During the Vietnam War, for
example, the United States employed chemical defoliants in South Vietnam. During the Persian Gulf
War, Iraq’s Saddam Hussein spilled huge amounts of oil into the Persian Gulf and set fire to Kuwaiti
oil fields. Industrial pollution and human waste continued to plague many of the world’s waterways.
In Eastern Europe industrialization severely polluted half the area’s rivers and endangered farmland.
Pollution was responsible for respiratory diseases and higher rates of infant mortality. Population