In the colonial era, the Hindu Kush were considered, informally, the dividing line between Russian and British areas of influence in Afghanistan. During the Cold War the Hindu Kush range became a strategic theatre, especially during the 1980s when Soviet forces and their Afghani allies fought the Mujahideen with support from the United States channelled through Pakistan. After the Soviet withdrawal and the end of the Cold War, many Mujahideen morphed into Taliban and Al Qaeda forces imposing a strict interpretation of Islamic law (Sharia), with Kabul, these mountains, and other parts of Afghanistan as their base. Other Mujahideen joined the Northern Alliance to oppose the Taliban rule.