During a 1978 coup d' état in Afghanistan, where the communist party took power, it started a series of radical modernization reforms throughout the country that were forced and deeply unpopular, particularly among the more traditional rural population and the established traditional power structures. The regime's nature of vigorously suppressing opposition, including executing thousands of political prisoners, led to the rise of anti-government armed groups, and by April 1979 large parts of the country were in open rebellion. The ruling party itself experienced deep rivalries, and in September 1979 the General Secretary of the People's Democratic Party of Afghanistan (PDPA), Nur Mohammad Taraki, was murdered under orders of the second-in-command, Hafizullah Amin, which soured relations with the Soviet Union. Eventually the Soviet government, under General Secretary Leonid Brezhnev, decided to the 40th Army on 24 December 1979. Arriving in the capital of Kabul, they staged a coup, killing PDPA general secretary Amin and installing Soviet loyalist Babrak Karmal from a rival faction. The deployment had been variously called an "invasion" (by Western media and the rebels) or a legitimate supporting intervention (by the Soviet Union and the Afghan government) on the basis of the Brezhnev Doctrine.