THE TERM Middle East came to modern use after World War II, and was applied to the lands around the eastern end of the MEDITERRANEAN SEA including TURKEY and GREECE, together with IRAN and, more recently, the greater part of North Africa.
The old Middle East began at the river valleys of the Tigris and the Euphrates rivers or at the western borders of Iran and extended to Burma (MYANMAR) and Ceylon (SRI LANKA).
Some geographers today say the Middle East region stretches 6,000 mi (9,656 km) eastward from the dry Atlantic shores of MAURITANIA to the high mountain core of AFGHANISTAN.
Other geographers begin the Middle East with EGYPT.
It includes numerous separate political states, most of which were created by colonial government cartographers in the 19th and 20th centuries.
A good deal of the Middle East is too dry or rugged to sustain human life, and only 5 to 10 percent of the entire region is cultivated.
As a result, a stark contrast exists between core areas of dense human settlement where water is plentiful, and the empty wastes of surrounding deserts and mountains.
Four regions can be identified in this vast, diverse, and distinct area: the Northern Highlands, a 3,000-mi- (4,828-km-) long zone of plateaus and mountains in Turkey, IRAN, and AFGHANISTAN, stretching from the Mediterranean Sea to Central Asia; the Arabian Peninsula, a million-square-mi- (2.6-million-square-km-) desert quadrilateral jutting southward into the INDIAN OCEAN and flanked on either side by the Persian (or Arabian) Gulf and the RED SEA; the Central Middle East, the rich valleys of the NILE in Egypt and of the Tigris and Euphrates in IRAQ, and the intervening fertile crescent countries of ISRAEL, JORDAN, LEBANON, and SYRIA; and North Africa, a band of watered mountains and plains set between the SAHARA DESERT and the Mediterranean Sea.
Known by the Arabs as al Maghrib al Aqsa ("Land of the Setting Sun"), it includes the nations of TUNISIA, ALGERIA, MOROCCO, and LIBYA.
THE NORTHERN HIGHLANDS The Taurus and ZAGROS MOUNTAINS of southern Turkey and western Iran form a physical and cultural divide between Arabic-speaking peoples to the south and the plateau-dwelling Central Asian people of Turkey, Iran, and Afghanistan.
Around one-third of the people of the Middle East and North Africa live in the Northern Highlands, on the Anatolian and Iranian plateaus and the flanks of the HINDU KUSH range of Afghanistan.
Turkey is a large, rectangular peninsula plateau bounded on three sides by water-the BLACK SEA on the north, and the AEGEAN SEA to the west, and south.
The Turkish coast is rainy, densely settled, and intensively cultivated.
About 40 percent of the population is clustered onto the narrow, wet Black Sea coast, on the lowlands around the Sea of Marmara in both European and Asiatic Turkey, along the shores of the Aegean, and on the fertile Adana Plain in the southeast.
By contrast, the center of Turkey-the dry, flat Anatolian Plateau-is sparsely settled.
Cut off by the Pontic Mountains to the north and the Taurus to the south, the dead heart of the plateau is too dry to sustain dense agricultural settlement; in the east, the rugged terrain of the Armenian highlands limits agricultural development.
Although the environmental base of Iranian society is similar to Turkey's, the topography is more dramatic, and contrasts are more sharply drawn.
High mountains ring the dry Iranian Plateau on all sides except the east.
In the west and south, the folded ranges of the Zagros Mountains curve southeastward for a distance of 1.400 mi (2,253 km) from the northwest Turkish frontier to deserts of Sistan in the southeast.
In the north, the steep volcano-studded ELBURZ range sharply divides the wet CASPIAN SEA coast from the dry Iranian interior.
The encircled plateau covers over half the area of Iran, with large uninhabited stretches of salt waste in the Dashti Kavir to the north and of sand desert in the Dashti Lut to the south.
Along the Caspian Littoral, which receives up to 60 in (152 cm) of rainfall per year, the intensive cultivation of rice, tea, tobacco, and citrus fruits supports a dense rural population.
Similarly, in AZERBAIJAN in the northwest and in the fertile valleys of the northern Zagros, rainfall is sufficient to support grain cultivation without irrigation.
But in the rest of Iran, rainfall is inadequate and crops essentially require irrigation.
Oasis settlement based on wells, springs, or underground horizontal water channels called qanats is common.
In the small remote country of Afghanistan, the easternmost nation of the Northern Highlands, the processes of population growth, agricultural expansion, and urbanization have barely begun.
The country's center is occupied by the ranges of the Hindu Kush; a rugged, snowbound highland that is one of the least penetrable regions in the world.
Deserts to the east and south are cut by two major rivers, the Hari Rud and the Helmand, both originating in the central mountains of Afghanistan and disappearing into the deserts of eastern Iran.
In the north, the AMU DARYA (Oxus) flows into the Russian STEPPE.
Settlements are found in scattered alluvial pockets on the perimeter of the Hindu Kush, where there is level land and reliable water supplies.
Over 70 percent of Afghanistan's population lives in the scattered villages as cultivators of wheat and barley and herders of small flocks of sheep and goats.
An additional 15 percent are nomadic tribesmen, whose political power is still felt in this traditional society.
In central and eastern Afghanistan, Pathans are dominant; in the north, the Turkish-speaking Uzbeks and Persian-speaking Tadzhiks predominate.
THE ARABIAN PENINSULA The Arabian Peninsula may be described as a great plateau sloping gently eastward from a mountain range running along the whole length of its west side.
It is a huge desert fault bounded on three sides by water and on the fourth by the deserts of Jordan and Iraq.
In the west, the rugged slopes of the Hijaz and the highlands of YEMEN form the topographical spine of this platform.
The remainder tilts eastward to the flat coasts of the Persian Gulf, rising only in the extreme southeast to the height of the Jabal al Akhdar (Green Mountains) of Oman.
Although the peninsula is the largest in the world and nearly four times the size of the state of TEXAS, it supports a population of less than 18 million people.
The majority of these people live in two nations: SAUDI ARABIA (25.79 million, excluding 5.57 million non-nationals), which governs nine-tenths of this region, and Yemen (20 million), whose highlands trap sufficient moisture to support cultivation without irrigation.
Smaller states on the eastern and southern perimeters of the peninsula include KUWAIT, QATAR, the UNITED ARAB EMIRATES, and OMAN.
Although the TROPIC OF CANCER bisects the Arabian Peninsula, passing south of Medina, Riyadh, and Muscat, most of the southern half of the peninsula is too high or isolated to be characteristically tropical, the main exception being the lowland coast.
The principal historical determinant of human settlement in the peninsula has been the availability of water.
Overall, the region receives less than 3 in (7.62 cm) of rainfall each year, with a bit more in the north.
Only the highlands of Yemen and Oman at the southern corners of the peninsula receive more than 10 in (25.4 cm).
Daily temperatures commonly rise above 100 degrees F (37.7 degree C).
Fully one-third of the central plateau is covered by a sea of shifting sand dunes and much of the rest lies under boulder-strewn rock pavement.
In the southern desert, the forbidding Rub al Khali (Empty Quarter), wind-worked dunes 500 to 1,000 ft (152 to 305 m) high, cover an area of 250,000 square mi (402,336 square km) to form a bleak, rainless no-man's-land between Saudi Arabia and the states of the southern coast.
Arching northward from the Rub al Khali, a 15- mi- (24-km-) wide river of sand, the Ad Dahna, connects the southern sands with the desert of Nafud 800 mi (1,287 km) to the north.
Given this harsh environment, the Arabian landscape has no permanent lakes or streams.
Vegetation is sparse.
Settlement is confined to oases, and only 1 percent of the region is under cultivation.
Vast stretches of the peninsula are completely uninhabited, devoid of human presence except for the occasional passage of Bedouin camel herders.
Within this difficult physical setting, two-thirds of the people of the Arabian Peninsula are rural agriculturalists, seminomads, and nomads.
Their lives focus on oasis settlements where wells and springs provide water for the cultivation of dates-the staple food of Arabia-and the maintenance of herds of camels, sheep, and goats.
The distribution of these oases is determined by a network of dry river valleys (wadis) carved into the surface of the plateau in earlier and wetter geological periods.
These wadis provide the most favored locations for commercial and agricultural settlement and the most convenient routes for caravan traffic.
In the western highlands, where population density is above average, the largest urban centers are Mecca, Medina, and Taif.
In central Arabia, underground water percolates down from these uplands and surfaces through artesian (gravity-flow) wells, creating a string of agricultural oases both north and south of the Saudi Arabian capital of Riyadh.
Farther east, on the shores of the Persian Gulf, this same water emerges as freshwater springs in Kuwait, eastern Saudi Arabia, and the United Arab Emirates.
Similarly in South Yemen, springs in the Wadi Hadramuat, a gash several hundreds miles long parallel to the coast of the Gulf of Aden, provide the basis for oasis settlement.
Only in Yemen and Oman is this dryland oasis pattern broken.
Today, oil resources in Saudi Arabia, Kuwait, the island state of BAHRAIN, the United Arab Emirates, and, to a lesser extent, Qatar and Oman are providing the capital for rapid economic growth, leaving the southern states of Yemen and South Yemen in isolated poverty.
In the gulf, cities like Dhahran, Dhammam, Ras Tannurah, Kuwait City, Manamah (the capital city of Bahrain), and emirate centers like Abu Dhabi, Dubai, and Sharjah are creations of the oil industry.
Less directly but equally dramatically, the traditional centers of Riyadh (population: 3.5 million), Mecca (550,000) and Jeddah (2.8 million) are growing rapidly as farmers and Bedouins seek salaried employment in expanding urban industries.
THE CENTRAL MIDDLE EAST The Central Middle East is flanked to the west and east by two great river valleys, the Nile of Egypt and the Tigris-Euphrates system in Iraq.
Between these riverine states, the small nations of Israel, Lebanon, and Syria line the shores of the eastern Mediterranean; Jordan is LANDLOCKED.
The environments of these nations are as complex as their histories.
Four millennia of human civilization have left an essentially denuded landscape-barren hills, steppes overgrazed by sheep and goats, and rivers chocked by the erosional silt of human activity.
In Egypt, the Nile Valley, a narrow trough 2 to 10 mi (3.2 to 16 km) wide cuts northward across the dry plateau of northeastern Africa to the Mediterranean Sea.
East of the Nile Valley, the heavily dissected Eastern Highlands border the coast of the Red Sea, continuing past the Gulf of Suez into the SINAI PENINSULA.
Barren and dry, these highlands are occupied by nomadic herders.
The sources of the Nile River lie 2,000 mi (3,218 km) south of the Mediterranean in the wet plains of the Sudan and the equatorial highlands of East Africa.
The Nile's largest tributary, the White Nile, originates in Lake Albert and Lake VICTORIA and flows sluggishly through a vast swamp, the Sudd, in southern Sudan, before entering Egypt.
The other major tributaries, the Blue Nile and the Atbara River, flow out of the Ethiopian highlands, draining the heavy summer rains of this region northward toward the desert.
This summer rainfall pours into the Nile system, causing the river to flood regularly from August to December, and raises its level some 21 ft (6.4 m).
For centuries, this flood formed the basis of Egyptian agriculture.
Specially prepared earth basins were constructed along the banks of the Nile to trap and hold the floodwaters, providing Egyptian farmers with enough water to irrigate one and, in some areas, two crops of wheat and barley each year.
In the 20th century, British and Egyptian engineers constructed a series of barrages and dams on the Nile to hold and store the floodwater year-round.
This transformation of Nile agriculture was largely completed in 1970 with the construction of the Aswan High Dam, a massive earthen barrier more than 2 mi (3.2 km) across, 0.5 mile (0.8 km) wide at the base, and 120 ft (37 m) high.
Behind it, Lake Nasser, the dammed Nile River, stretches 300 mi (483 km) southward to the Sudanese border.
The dam added about one-third to the cultivated area of Egypt.
Hence, Egyptian population expanded from estimated 10 million at the turn of the century to its current 76 million.
During this same period, urban population expanded eight times, and Cairo (7.76 million) and Alexandria (3.9 million) emerged as the two largest cities on the African continent.
In contrast to Egypt, the central problem in the other great river valley of the Middle East, the Tigris- Euphrates of Iraq, is not overpopulation but environmental management.
Both these rivers rise in the mountains of eastern Turkey and course southward for more than 1,000 mi (1,609 km) before merging in the marshes of the Shatt al Arab.
North of Baghdad, both rivers run swiftly in clearly defined channels.
To the south, they meander across the flat alluvial plains of Mesopotamia.
East of the valley, the Zagros Mountains rise as a steep rock wall separating Iraq from Iran.
To the west, a rocky desert plain occupied by nomadic herders stretches the borders of Saudi Arabia, Jordan, and Syria.
Only in the northeast, in the Kurdish hills, does rainfall sustain non-irrigated cultivation.
Elsewhere in Iraq, human existence depends on the water of the Tigris and Euphrates rivers.
But unlike Egypt, where every available acre of farmland is intensively utilized, Iraq's agricultural resources are largely wasted.
The Tigris and Euphrates rivers have always proved less manageable than the Nile.
Fed by melting snows in Turkish highlands, spring floods 8 to 10 ft (244 to 309 cm) above normal pour down the river channels to Baghdad and then spread out over the vast plains of Mesopotamia, where the land is so flat that elevations change only 4 to 5 ft (122 to 152 cm) over distances of 50 mi (80 km).
In the Fertile Crescent countries of Syria, Lebanon, Jordan, and Israel, which lie along the eastern coast of the Mediterranean between the river valleys of Egypt and Iraq, environmental patterns are extremely complex.
The coastal plain, narrow in the north but widening southward, is backed by dissected, rugged highlands that reach elevations of more than 10,000 ft (3,048 m) in Lebanon.
Throughout their length, these uplands have been denuded of forests, notably the famous cedars of Lebanon, by centuries of overgrazing and cutting for economic gain.
Winter rainfall is plentiful in the north but less in the south.
In Syria, the highlands capture this ample rainfall in stream that support life in the oasis cities of Aleppo, Homs, Hama, and Damascus.
In Lebanon and northern Israel, runoff from the highlands sustains important commercial and agricultural areas along the coast.
Further south, the highlands flatten out into the rainless wastes of the NEGEV DESERT.
Inland, a narrow belt of shallow, flat-bottomed intermontane valleys separates these western highlands from the dry uplands plateaus and mountains of the east.
Between Israel and Jordan south of the Galilee, the Jordan River flows along one of these valleys 150 mi (241 km) southward to the Dead Sea, 1300 ft (396 m) below sea level.
Farther north, a similar trough in Lebanon, the Beqaa Valley, is drained by the Litani and Orontes rivers.
East of these lowlands, rugged highlands grade inland to the grass-covered steppes of Syria in the north and the dry stone pavement of the Jordanian desert in the south.
In this varied terrain, the distribution of population is extremely uneven.
NORTH AFRICA North Africa is the largest subregion of the modern Middle East, covering an area larger than the United States, but inhabited by only 50 million people grouped together on the southern shore of the Mediterranean Sea between water and sand.
Much as Egypt is truly the gift of the Nile, cultural North Africa is the result of a physiographic event, the ATLAS MOUNTAINS, which separate the Sahara Desert from the Mediterranean Sea and Europe beyond.
Most of the territory of the modern nations of Maghreb-Morocco, Algeria, Tunisia, and Libya consists of Saharan wastelands that stretch 3,000 mi (4,828 km) across Africa from the Atlantic Ocean to the Red Sea.
One-seventh of this area is sand dunes; the remainder is rock-strewn plains and plateaus.
Aridity in the Sahara is not interrupted even by the jutting peaks of the AHAGGAR and TIBETSTI massifs at 6,000 ft (1,829 m) which receive as little as 5 in (21.7 cm) of rainfall per year.
Here, as well as in other scattered Saharan oasis environments, an estimated 3 million people wrest a living from what is Earth's most difficult cultural environment outside the polar regions.
Only in the north, along the mountain-backed coast of the Mediterranean, is rainfall sufficient to sustain substantial concentrations of people.
The Atlas Mountains form a diagonal barrier isolating the nomads of the deserts and steppes of the south and east from sedentary agriculturalists in the Mediterranean north.
The Spanish Sahara was the only North African country that was totally desert.
Before the recent discovery of extensive phosphate deposits in the north and the possibility of rich iron ore lodes, this territory was of little interests to anyone, but both Morocco and Mauritania have claimed sovereignty.
With the departure of SPAIN in 1976, the territory has been divided between its two larger neighbors.
In Morocco, the Atlas Mountains form a succession of four mountain ranges dominating the landscape.
In the north, the Rif, which is not geologically associated with the Atlas, is a concave arc of mountains rising steeply along the Mediterranean, reaching elevations of 7,000 ft (2,134 m) and orienting Morocco toward the Atlantic.
In the center of Morocco, the limestone plateaus and volcanic craters of the Middle Atlas reach elevations of 10,000 ft (3,048 m); contact with Algeria is channeled through the Taza corridor, and this mountain barrier has isolated the Moroccan Sahara until modern times.
Farther south, the snow-capped peaks of the High Atlas attain elevations of 13,400 ft (4,084 m) and separate the watered north from life in the Sahara.
Finally, the Anti-Atlas, the lowest and southernmost of the Moroccan ranges, forms topographic barriers to the western Sahara.
Historically, the Atlas range has provided a refuge for the original Berber-speaking inhabitants of Morocco, whose descendants today make up half the nation's population.
Throughout mountainous Morocco, Berber populations maintain an agrarian tradition of transhumance of goats and sheep wedded to cultivation of barley, centered around compact mountain fortresses.
Density of settlement in the mountains depends on rainfall, which in general diminishes from west to east, and on altitude, which prohibits year-round settlement because of cold winter temperatures in areas much over 6,000 ft (1,829 m).
Most of Morocco's 32.2 million people are Arabic-speaking farmers who till the fertile lowlands plains and plateau stretching from the Atlantic to the foothills of the Atlas.
Farther east along the Atlas complex, the primary environmental contrast in Algeria is once again the distinction between the fertile, well-watered, and densely settled coast and mountain ranges of the north and the dry reaches of the Sahara Desert in the interior.
The Algerian coast is backed by the Tell Atlas, a string of massifs 3,000 to 7,000 ft (914 to 2,133 m) in elevation, which have formed an important historical refuge for Berber-speaking tribes.
In the interior, a parallel mountain range, the Saharan Atlas, reaches comparable elevations in a progressively drier climate.
Between these two ranges in western Algeria, the high plateaus of the Shatts, a series of flat interior basins, form an important grazing area.
In eastern Algeria, the two ranges of the Atlas merge to form the rugged Aures Mountains.
South of these ranges, Algeria extends 900 mi (1,448 km) into the heart of the Sahara.
In Tunisia and Libya, the topography is less dramatic than in Morocco and Algeria, but the same environmental sequence from northern coast to southern desert prevails.
Two-thirds of Tunisia's 9.9 million people live in the humid northeast and in the eastern extension of the Arres Mountains.
The central highlands and interior steppes, marginally important in the past, have become sites of innovative development projects.
Tunisia remains an example of self-motivated and successful state planning.
In Libya, the population (5.6 million) is concentrated on the coast in the hilly back country of Tripolitania and Cyrenaica.#