2007, Morocco presented an autonomy plan for the territory to the
UN, which the U.S. considers serious and credible. The Polisario
also presented a plan to the UN in 2007. Since June 2007,
representatives from the Government of Morocco and the Polisario
Front have met four times to negotiate the status of Western Sahara.

World
Globally, the 20th century was marked by: (a) two devastating
world wars; (b) the Great Depression of the 1930s; (c) the end of
vast colonial empires; (d) rapid advances in science and technology,
from the first airplane flight at Kitty Hawk, North Carolina (US) to
the landing on the moon; (e) the Cold War between the Western
alliance and the Warsaw Pact nations; (f) a sharp rise in living
standards in North America, Europe, and Japan; (g) increased
concerns about the environment, including loss of forests, shortages
of energy and water, the decline in biological diversity, and air
pollution; (h) the onset of the AIDS epidemic; and (i) the ultimate
emergence of the US as the only world superpower. The planet's
population continues to explode: from 1 billion in 1820, to 2
billion in 1930, 3 billion in 1960, 4 billion in 1974, 5 billion in
1988, and 6 billion in 2000. For the 21st century, the continued
exponential growth in science and technology raises both hopes
(e.g., advances in medicine) and fears (e.g., development of even
more lethal weapons of war).

Yemen
North Yemen became independent of the Ottoman Empire in 1918.
The British, who had set up a protectorate area around the southern
port of Aden in the 19th century, withdrew in 1967 from what became
South Yemen. Three years later, the southern government adopted a
Marxist orientation. The massive exodus of hundreds of thousands of
Yemenis from the south to the north contributed to two decades of
hostility between the states. The two countries were formally
unified as the Republic of Yemen in 1990. A southern secessionist
movement in 1994 was quickly subdued. In 2000, Saudi Arabia and
Yemen agreed to a delimitation of their border.

Zambia
The territory of Northern Rhodesia was administered by the
[British] South Africa Company from 1891 until it was taken over by
the UK in 1923. During the 1920s and 1930s, advances in mining
spurred development and immigration. The name was changed to Zambia
upon independence in 1964. In the 1980s and 1990s, declining copper