The Salafi movement or Salafist movement or Salafism is an ultra-conservative reform branch or movement within Sunni Islam
First thing first you need to fathom is the notion and roots of Salafi movement in Islam and in the region:
The Salafi movement or Salafist movement or Salafism is an ultra-conservative reform movement within Sunni Islam that developed in Egypt in the second half of the 19th century, against a background of European colonialism. It advocated a return to the traditions of the "devout ancestors" (the salaf). Some scholars define this movement as Modernist Salafism.
For example Rashīd Rida an Islamic scholar who formulated an intellectual response to the pressures of the modern Western world on traditional Islam.:
"...He was concerned with what he considered the backwardness of the Muslim countries, a circumstance he believed resulted from a neglect of the true principles of Islam. He believed that these principles could be found in the teachings of the Prophet Muhammad and in the practices of the first generation of Muslims, before corruptions began to spread among the religious practices of the faithful (
c. 655). He was convinced that Islam, as a body of teachings correctly understood, contained all the principles necessary for happiness in this world and the hereafter, and that positive effort to improve the material basis of the community was of the essence of Islam.
To realize a political and cultural revival, Rashīd Riḍā saw the need to unify the Muslim community. He advocated the establishment of a true caliph, who would be the supreme interpreter of Islam and whose prestige would enable him to guide Muslim governments in the directions demanded by an Islam adapted to the needs of modern society. His ideas were foundational to the establishment in 1928 of the religious and political organization known as the Muslim Brotherhood..."
Therefore the idea of political Islam or in other words Islamic state in our age has been a matter of debate amongst Islamic scholars for centuries at least since 18th century it's been profoundly influenced in Egypt by the writings of Muhammad Abduh , Jamal al dīn al afghani (asad abadi) , Rashīd Rida and later on Sayyed Qutb and also Hassan Banna to name a few ...
Moreover such an idea doesn't just origin amongst aforementioned scholars in Egypt but also you can find its traces in Indian subcontinent inspired by Shah Waliullah Dehlawi and also Deobandi (a revivalist movement within Sunni ,primarily Hanafi, Islam) . resulted in Ulama (body of religious scholars) in Pakistan led by Fazlur Rahman , Maulana Sami ul Haq (Father of the Taliban) and his Jamiat Ulema-e-Islam , besides Lashkar-e-Taiba , Jaish-e-Mohammed and Sipah-e-Sahaba ....
The next place after India and Egypt is Saudi Arabia :
Sayyid muhammad Qutb died in Saudi Arabia in 2014.
Sayyid muhammad Qutb was arrested a few days before Sayyid (on July 29, 1965) for his alleged co-leadership along with his brother in a plot to kill leading political and cultural figures in Egypt and overthrow the government. His brother died on the gallows in 1966, but Muhammad's life was spared and he, along with other members of the Muslim Brotherhood took refuge in Saudi Arabia.
Actually the story begins here , a false interpretation of Sayyid Qutb by his brother in Saudi Arabia ignited what we see now ... Sayyid Qutb divided and categorized governments into 2 groups first Islamic society and secondly ignorant society and believed governor should be a divine one and any government that doesn't enjoy such a privilege is considered as an ignorant society .. to solve the problem he suggested two solutions first immigration and secondly Jihad ... his whole point was against corrupted governors not Islamic sects and he didn't takfir any one expect governors ....
Bin Ladan was one of the muhammad Qutb followers and students and if you look what he did in Afghanistan in 80s you'll noticed at first they didn't target people and other sects like what we see right now ....
What happened was this a takifiri interpretation of Sayyid Qutb notion of Jihad against corrupted governors ... you can see it how Boko Haram kidnapped girls students because we didn't have western school in early Islam ... groups like Boko Haram in Nigeria , Al shabab in Somalia and Ansar Al-sonnat in Algeria are all the same ,,,
In fact Afghanistan accelerated this when Indian/Pakistani branch of Salafism met its counterpart Egyptien/Saudis false interpretation resulted in creation of ALQ and now ISIS.