From the late 1970s, the United States provided financial and technical support to Islamist groups in Afghanistan, known as the Mujahideen, which in Arabic means "those who fight in the holy war," to weaken the pro-Soviet Afghan government that existed at that time. This was one of the reasons why the Soviet Union invaded Afghanistan and ultimately became one of the events that precipitated the fall of the communist bloc a few years later.
Osama Bin Laden was born in Saudi Arabia in 1957 within one of the five richest families in the country. His father, Mohammed Bin Laden, migrated as a teenager from Yemen to the Saudi port of Jeddah in search for a better economic life. Once there, he founded a construction company that is currently called the Saudi Binladin Group, which has presence in many countries around the world. His success came from strengthening commercial ties with the Saudi royal family through which he obtained exclusive maintenance rights in numerous mosques, infrastructures in the country and the energy sector. Mohammed Bin Laden died in 1967 due to a plane crash caused by an error from the American pilot of his private plane while landing in a southern province of Saudi Arabia.
Osama Bin Laden became then a head of its family but after studying Economics and Business at an elite university in Saudi Arabia decided to travel into Afghanistan in 1979 at the age of 22 to join the Mujahideen who were fighting the Soviets. He used his family's fortune, which was estimated by Forbes magazine at $ 5 billion at the time, to formally create in 1988 his own Sunni Islamist organization which he called al-Qaeda, meaning in Arabic 'The Foundation'.
With the Soviet Union's withdrawal from Afghanistan in 1988, al-Qaeda focused on the Israel-Palestine conflict. Osama Bin Laden believed that there was a Judeo-Christian conspiracy to eradicate Islam from the Middle East, so a 'jihad', or global holy war, had to be waged against all invaders, and according to this the US alliance with Israel represented the biggest threat to Muslims in the region.
Iraq, a largely Sunni country ruled by Saddam Hussein, invaded Kuwait in 1990, which was an ally of the United States, after the Kuwait government refused to pay the compensation demanded by the Iraqi government for slant drilling on oil fields near the border. The United States reacted in January 1991 by invading and defeating Saddam Hussein in just six weeks with an international coalition of 35 countries, the largest since World War II. The UN subsequently imposed severe sanctions on Iraq, enraging further al-Qaeda members.
Osama Bin Laden began to openly criticize the Saudi royal family. First, for supporting the Oslo Agreements that laid the foundation for peace between Israel and Palestine; and then, for allowing US military bases in Saudi Arabia, considering that the monarchy was turning the 'holy place of Islam' into a US colony. Because of this, the Saudi government expelled Osama Bin Laden and took away from him his citizenship, so he decided to flee to Sudan, a country that was governed with an extremist interpretation of the Koran, living there between 1992 and 1996.
From that moment, al-Qaeda began to commit internacional terrorist acts more frequently. In 1993, for example, it attacked the World Trade Center in New York, causing the death of six people. The nephew of one of Bin Laden's closest men, Khalid Sheikh Mohammed, entered the United States as an Iraqi refugee and then set up a bomb-van that exploded in the main parking lot of the offices with the aim to tear down both Twin Towers. Most of those responsible were given life sentences and some others were extradited to different countries in the Middle East.
Sudan expelled Bin Laden from his territory in 1995 because of his involvement in the murder attempt in Egypt, a neighboring country, of President Hosni Mubarack. At this time, Bin Laden became more radicalized after the United States did not fulfill its promise to withdraw its military bases from Saudi Arabia when the threat of Saddam Hussein in Iraq vanished, so he decided to move to Afghanistan when the Taliban seized power in 1996 and offered him refuge. From there, Bin Laden declared the holy war to the western countries.
His next major attack was in 1998 against US Embassies in Tanzania and Kenya using car bombs that caused 224 deaths. Bin Laden justified the attack on American civilians by saying that because the United States is a democracy, its population is responsible for the decisions that rulers make regarding foreign policy.
With this new more extremist perspective about jihad, Bin Laden used the US airstrikes on Lebanon in 1982 in which skyscrapers in Beirut, the capital, were bombed with Muslim families still inside them, to justify an attack on the Twin Towers as an act of revenge. Thus, for al-Qaeda the purpose of terrorism was that 'Americans feel what Muslims have felt in the Middle East for decades when children and women were killed by the forces of the United States'. The objective was also to weaken the western economy, which according to bin Laden, allowed the military domination of the United States in the Middle East.
The 9/11 attacks ultimately caused the death of 2,996 people and 25,000 wounded, unleashing a series of events that changed the nature of international relations and that largely explain the current situation in the world.