Although this was published a few days ago, there is some interesting reading over at Foreign Policy as former KGB head Oleg Kalugin describes his experience planning the Soviet invasion of Afghanistan.  I sure hope Barack Obama is studying up on the Russian experience.

KGB officers on the ground argued that if Moscow did not intervene more aggressively, Amin would surely be overthrown and an Islamic government installed. I attended a meeting of KGB intelligence and Soviet military intelligence in which the GRU [Soviet military intelligence] chief, General Ivashutin, argued strenuously for an invasion. “There is no other alternative but to introduce our troops to support the Afghan government and crush the rebels,” he said.

Still, Andropov remained against the introduction of troops. Only under pressure from Defense Minister Dimitri Ustinov did he reluctantly come around to the view that the Soviet military would have to invade.