It's worth noting the difference between March and December was that by December Brezhnev was effectively incapable of running anything and the decision to invade was made in his name, but from a USSR that while at the height of its power was completely leaderless.
I would note that the fall of the DPRA government was effectively putting the USSR at a risk of having not only something like the Islamic Republic of Iran, which had as much hatred for the Soviets as for the Americans, but an Islamist government which by virtue of having Uzbeks and Tajiks in it might well start trying to bring the Islamist Revolution into the USSR itself. The decision to invade had a very clear geopolitical logic, and is one of the lesser moments of Kicking the Dog by the Soviet Union in the Cold War (as compared to say, Czechoslovakia in 1968).
And as noted, the USSR was winning until the USA intervened because something with that much risk was not a prospect taken lightly by the Soviet leadership.
no subject
I would note that the fall of the DPRA government was effectively putting the USSR at a risk of having not only something like the Islamic Republic of Iran, which had as much hatred for the Soviets as for the Americans, but an Islamist government which by virtue of having Uzbeks and Tajiks in it might well start trying to bring the Islamist Revolution into the USSR itself. The decision to invade had a very clear geopolitical logic, and is one of the lesser moments of Kicking the Dog by the Soviet Union in the Cold War (as compared to say, Czechoslovakia in 1968).
And as noted, the USSR was winning until the USA intervened because something with that much risk was not a prospect taken lightly by the Soviet leadership.