Following the Soviet invasion of Afghanistan, ISI and CIA ran multibillion-dollar worth Operation Cyclone to thwart the communist regime as well as defeating Soviets in Afghanistan. Throughout the military regime of General Zia-ul-Haq, the ties and relations were promoted at its maximum point, and the United States had given billion dollars of economic and military aid to Pakistan. The Soviet invasion of Afghanistan in December 1979 highlighted the common interest of Pakistan and the United States in opposing the Soviet Union. In 1981, Pakistan and the United States agreed on a $3.2 billion military and economic assistance program aimed at helping Pakistan deal with the heightened threat to security in the region and its economic development needs. With US assistance, in the largest covert operation in history, Pakistan armed and supplied anti-Soviet fighters in Afghanistan.