The Taliban (Pashto: طالبان ṭālibān, meaning "students"), also Taleban, is a radical Sunni Islamist movement that governed Afghanistan from 1996 until late 2001, when they were removed from power by NATO forces during Operation Enduring Freedom. It has regrouped since 2004 and revived as a strong insurgency movement governing at the local level and fighting a guerrilla war against the governments of Afghanistan, Pakistan, and the NATO-led International Security Assistance Force (ISAF). The movement is made up of members belonging to different ethnic Pashtun tribes, along with a number of volunteers from nearby Islamic countries such as Uzbeks, Tajiks, Chechens, Arabs, Punjabis and others. They operate in Afghanistan and Pakistan, but mostly around the Durand Line regions. U.S. officials say their headquarters is in or around Quetta, although Pakistan denies it.