To tell the truth, I hesitated to link this post: on one hand it lays the chronology of the events and explains honestly the conditions the Revolution faced, but on the other, it shows an ideological bias (socialist and anti-Stalinist one) perhaps more than other posts from this site analyzing situation in different countries or episodes from History. I can't assure that all the information is 100% accurate: Russian and former Soviet sources offer different versions of the relationship between PDPA's Khalq faction and the Soviet Union. What is hardly in discussion is the origin of the so-called "Muslim" Fundamentalism in West's dealing trying to topple the "pro-Soviet" regime. The post is certainly valid as food for thought.