Islamist factions, rapidly falling under the more radical influence of Zawahiri and his rich Saudi acolyte Osama bin Laden, join the Neo-Conservative-influenced Reagan Administration to combat the Soviet Union's invasion of Afghanistan. They are successful in repulsing the Soviet armies and, when the Eastern Bloc begins to collapse in the late 1980s, both groups believe they were the primary architect of the "Evil Empire's" defeat and thus have the power to carry out their revolutions in their homelands. Curtis instead argues that the Soviets were on their last legs and were doomed to collapse without intervention.