The Taliban's extremely strict and "anti-modern" ideology has been described as an "innovative form of sharia combining Pashtun tribal codes," or Pashtunwali, with radical Deobandi interpretations of Islam favored by members of the Pakistani fundamentalist Jamiat Ulema-e-Islam (JUI) organization and its splinter groups. Also contributing to the admixture was the Wahhabism of their Saudi financial benefactors, and the jihadism and pan-Islamism of sometime comrade-in-arms Osama bin Laden. Their ideology was a departure from the Islamism of the anti-Soviet mujahideen rulers they replaced who tended to be mystical Sufis, traditionalists, or radical Islamicists inspired by the Ikhwan.

Sharia law was interpreted to ban a wide variety of activities hitherto lawful in Afghanistan, see below. Critics complained that most Afghans were non-Pashtuns who followed a different, less strict and less intrusive interpretation of Islam. Despite their similarity to the Wahhabis, the Taliban did not eschew all traditional popular practices. They did not destroy the graves of pirs (holy men) and emphasized dreams as a means of revelation.

Taliban have been described as both anti-nationalist and Pushtun nationalist. According to journalist Ahmed Rashid, at least in the first years of their rule, they followed Deobandi and Islamist anti-nationalist belief and opposed "tribal and feudal structures," eliminating traditional tribal or feudal leaders from "leadership roles." According to Ali A. Jalali and Mr. Lester W. Grau, the Taliban "received extensive support from Pashtuns across the country who thought that the movement might restore their national dominance. Even Pashtun intellectuals in the West, who seriously differ with the Taliban on many issues, expressed support for the movement on purely ethnic grounds."

In any case, the Taliban were very reluctant to share power, and since their ranks were overwhelmingly Pashtun the spread of their rule to non-Pashtun areas of Afghanistan meant Pashtun rule over non-Pashtuns. At the national level, "all senior Tajik, Uzbek and Hazara bureaucrats" were replaced "with Pashtuns, whether qualified or not. As a result of this loss of expertise, the ministries by and large ceased to function." In local units of government like city councils of Kabul or Herat, Taliban loyalists, not locals, dominated, even when the Pashto-speaking Taliban could not communicate with the local Persian-speaking Afghans (roughly half of the population of Afghanistan spoke Dari or other non-Pashtun tongues.) Critics complained this "lack of local representation in urban administration made the Taliban appear as an occupying force."

Like Wahhabi and other Deobandis, the Taliban do not consider Shias to be Muslims. The Taliban also declared the Hazara ethnic group, which totaled almost 10% of Afghanistan's population, "not Muslims."

Along with being very strict, the Taliban were averse to debate on doctrine with other Muslims. "The Taliban did not allow even Muslim reporters to question [their] edicts or to discuss interpretations of the Qur'an."

As they established their power the Taliban created a new form of Islamic radicalism that spread beyond the borders of Afghanistan, mostly to Pakistan. By 1998-1999 Taliban-style groups in the Pashtun belt, and to an extent in Pakistan-administered Kashmir, "were banning TV and videos ... and forcing people, particularly women to adapt to the Taliban dress code and way of life.