In the autumn of 1997, Nasar left London for Afghanistan, operating initially as a lecturer and trainer in the Arab-Afghan camps and guesthouses. He settled there with his family in 1998. In 1999, he formed a media and research center in Kabul and in 2000, he was allowed to open his own training camp, the al-Ghuraba Camp, located in Kargha, near Kabul. Nasar's camp was formally part of the Taliban's Ministry of Defense, and separate from al-Qaida and bin Laden's organization, whom he had fallen out with in 1998. In a seven-page letter from mid-1998, Nasar launched scathing criticism of bin Laden for the disdain al-Qaeda had shown towards the Taliban leadership of Afghanistan, including Mullah Omar. He is also highly critical of their strategies, and has denounced al-Qaeda's 1998 attacks on the US embassies in East Africa and the September 11 attack on New York's Twin Towers, which he argues put a catastrophic end to the jihadi cause.