On December 27, 1979, the USSR invaded Afghanistan to save an endangered communist regime. The People's Democratic Party of Afghanistan, founded in 1965 but almost immediately riven into two hostile wings, had been induced by Moscow into unifying in 1977 in order to seize power the following year. Within weeks, however, the majority Khalqi faction had driven out the rival Parchamis, only to discover that its rigid Marxism-Leninism was no match for Islam. As the Khalqi position deteriorated, Moscow thought to regain control by forceful replacement of the PDPA leaders with Parchamis. Instead, their invasion only consolidated popular determination to eject an alien ideology.