Sorry but so much of this is bad history.
In the early 50s and 60s when the Arab countries became independent countries, some of them were artificially created by The British. Eg. Saudi Arabai, Kuwait, Iraq and the Gulf countries, Syria etc.
Egypt has been independent since the 20s, Iraq and Saudi Arabia since the 30s (although Saudi Arabia was independent under divided kingdoms since the 20s and even before), Syria and Lebanon since the 40s. British influence was maintained in Egypt and Iraq by treaties backed by military force and local elite alliances, but was effectively ended in 1952 and 1958 respectively when the monarchies were both overthrown. Syria and Lebanon were the responsibility of France until they were granted independence after WW2. It is true, however, that the UAE (formerly known as the Trucial States), Bahrain, Qatar and Kuwait only achieved real independence from the British in the 60s and early 70s.
Although Britain had a hand in the creation of the modern borders of these countries, none of them can be said to be wholly artificial. They weren’t dreamed up by British officials out of thin air, and a range of factors contributed to their modern existence. Of the states in today’s Middle East, the country that comes closest to the type of artificiality suggested is probably Jordan.
Some of them like Iraq and Syria were taken over by coups and dictators took over. In Egypt they had a monarchy who was so corrupt they over threw him and a military junta was formed. Saudi Arabia was not Saudi Arabia earlier. It was called Hijaz. When Ibn Saud took the country by force, he made a pact with Mohamed Ibn Wahab a religious zealot. Ibn Saud to rule politically while Mohamed Ibn Wahab to rule religiously. This was the pact that formed Saudi Arabia.
Saudi Arabia was not called the Hijaz. The Hijaz is the region along the middle of the Red Sea coastal plain of the Arabian Peninsula and its hinterland, including the holy cities. The Saudis’ origin is in Najd, the north-central desert region of the peninsula where the first Saudi state rose in the 18th century, during the time when the Saudi-Wahhabi arrangement was made. That state conquered the Hijaz in the early 19th century, but was ended a few years later by an Egyptian force ostensibly acting on behalf of the Ottoman Empire. A second Saudi state rose in the middle of the 19th century in Najd, but never took the Hijaz, and was defeated by its Rashidi rivals. The third Saudi state - which survives to this day - rose at the start of the 20th century, and only conquered and annexed the Hijaz in 1924/25. It then united Najd with the Hijaz and a bunch of other regions and declared the Kingdom of Saudi Arabia in the early 30s. The Hijaz had previously been an autonomous Ottoman province run by the Hashimites which had declared independence and proclaimed itself a kingdom during WW1.
Egypt used to be the centre of Islamic learning at the Al Azhar University. Gamal Abdul Nasser who took over after the overthrow of the King was against the Brotherhood and Saudi Arabia. In fact he fought a war against the Saudis.
Nasser never fought a war directly against the Saudis. At times he opposed them and at other times he was forced to ally to them. The closest they came to actual conflict was when he sent Egyptian troops to North Yemen in 1962 to support the Republican coup there, while the Saudis supported the overthrown monarchy.
The Saudis then made a pact with the Americans for petrodollar. That was when they started getting powerful as the money flowed in. They wanted to spread their version of Islam. They started funding scholarships and Imams to Muslim countries. These scholarships were normally not sourced through the governments but privately. Most of the young children were sent to Pakistan to study at the Madrassas.
Sorry, what children are you talking about here? Saudis? Or Afghans?
These were during the days of the Muhajideen in Afghanistan where the notorious Osama was being supported by the Americans. The Mujahideen became the Taliban.
There’s no real evidence the Americans directly supported bin Laden, although there is some debate over whether he was an indirect recipient of funds before the founding of al Qaeda. Certainly American dollars supported plenty of other unsavory characters during the war, and the American effort definitely helped create the conditions in which al Qaeda could form and operate.
Only a few obscure mujahidin went on to form the Taliban in the 90s. The vast majority who continued fighting after the Soviet withdrawal - including nearly all the famous commanders/warlords who survived the 80s - went on to fight against the Taliban during the civil war of the 90s (and since 9/11 some, such as Hekmatyar and Haqqani, have allied with them).
Many of these students went back to their countries and started implementing what they studied there, which is an extreme form of Islam. This is the start. The Saudis didn't care if they did those violent stuff outside of their country. If you notice that most of these terrorist activities are caused by Sunnis and not Shias. It shows the political nature of this.
It may seem like this now, but it was Shi’i groups who actually pioneered the use of suicide bombings and massive car and truck bombings in the Middle East in the 80s and early 90s. Closer to the actual topic of this thread, it was Khomeini who prompted the first such blasphemy controversy in the West.
More generally, your post betrays a singular focus on Saudi Arabia and Wahhabism as the root cause of the extremism you’re trying to explain. As such, it neglects a range of other equally important factors - not just other active parties such as the Muslim Brotherhood, revolutionary Iran, or various regional movements, but also longer term trends in Islam, the impact of the West, the failure of so-called ‘secular’ authoritarian regimes to provide dignified lives for their subjects, and a host of other material factors.
*(edit): Haqqani actually joined the Taliban well before 9/11.