[1] He was a hardline member of the Khalq faction of the People's Democratic Party of Afghanistan (PDPA), and leader of at least the majority of the Khalqist faction since its former leader Sayed Mohammad Gulabzoy was exiled as Ambassador to the Soviet Union as part of the political preparation of the Soviet pullout from Afghanistan in September 1988.

A pillar of the communist regime, Tanai later attempted a coup against his former friend and President Najibullah, before seeking refuge in a hostile Pakistan and working with fundamentalists such as Gulbuddin Hekmatyar.

After the Saur Revolution in 1978, the coup d'état that resulted in the overthrow and assassination of President Mohammed Daoud Khan, Tanai, was appointed head of Military Intelligence.

[6] On 6 March 1990, when the trial of army officers from the PDPA's Khalq faction was about to start, Tanai launched a coup with the help of renegade mujahideen commander, Gulbuddin Hekmatyar, against the then President Mohammad Najibullah.

Prime Minister Benazir Bhutto's plea to the other six party leaders to aid Tanai and Hekmatyar was rebuked as a disgrace to the jihad.

Nonetheless, the Northern Alliance trumpeted the claim that Tanai had supported the Taliban, although this was quite easily disproven, and their own ranks included former communist leaders like Abdul Rashid Dostum.

He also campaigned for a bigger role for Pashtuns, former jihadi leaders and religious parties, and he openly criticised United States policies that perpetuated the Northern Alliance domination in Kabul.

According to western diplomatic sources, Tanai acted as an agent for ISI by providing the Taliban a skilled cadre of military officers from the Khalq faction of the People's Democratic Party of Afghanistan to use his pilots to fly Mig-23, Sukhoi fighters of what was left of the Afghan Air Force, drive Soviet tanks and the use of Soviet artillery.