Ignorance of the Arab world is widespread in Europe and America. Many people think that Iran is an Arab country, although its language, Farsi, is not Semitic at all but is more closely related to Indo-European languages such as Greek or Russian. The southward extent of Arabic in Africa is blurred. It is the language of North Sudan and is the co-official language of Mauritania and Tchad. It was at one time declared the official language of Somalia before that country descended into chaos.
The word 'Arab' in classical Arabic meant primarily Bedouin or desert Arab. In modern times its use has been extended to Arabic-speaking people in general, but the people of the settled areas have always regarded the nomads with suspicion and hostility. The Koran itself has harsh words about them. Paradoxically, an 18th century religious revival movement, Wahhabism, started in the desert. After Lawrence of Arabia had blown up the Hijaz Railway, which was built to protect Medina and Mecca, they were succcessfully taken over by King Saud's Wahhabis. With control of the Holy Cities combined with fabulous oil wealth, the Saudis achieved totally disproportionate influence all over the Islamic world.
When the Britisn and French found it too expensive to continue direct colonial rule over Arab countries, they tried to leave behind British-style constitutional monarchies and French-style republics, but one by one they were overthrown by military coups. Most governments in the region have for many years been military dictatorships. This suited the West; if they could buy the dictator they could control the country - and any oil. That is the regime that now teeters on the brink. The generals will not easily cede their powers - and their wealth. Watch carefully what America does now!