Oppression is in the eye of the beholder. One man's terrorist is another man's freedom fighter. My point is that all the cases I cited, a vastly inferior force successfully resisted what they viewed as oppression by a vastly superior force. Thus the idea that it is impossible to resist a modern military force is incorrect.
It should be noted that in all the cases you cited, the fighters were armed with more than just normal guns that are available to civilians. Afgans fighting against USSR were equipped by Stingers for example. And each case you cited was a case of outside force attacking the country (USA in Iraq, USSR if Afganistan etc.). What we are talking about is citizens rising up against corrupt government. That is not what happened in Afganistan, but it IS what happened in the communist regimes in Europe.
If number of guns ensures free and corruption-free government, then number of guns should correlate with lower corruption and god governance. Is that the case? The list is here:
http://en.wikipedia.org/wiki/List_of_countries_by_gun_ownership
So, let's compare USA and Finland. USA has almost three times as many guns per capita as Finland does. So, if guns ensure good governance, freedom from corruption and all sorts of other good things, how do those two countries compare? Since the difference in gun-ownership is so huge, the differences should be obvious. Is US Government less corrupted than the Finnish one? Are Finns less free than Americans are?
Or what if we compare.... Yemen with Germany. Is there more freedom and less corruption in Yemen than there is in Germany, since it has a lot more guns? Wikipedia says this about Yemen:
"The government and its security forces, often considered to suffer from rampant corruption, have been responsible for torture, inhumane treatment and extrajudicial executions. There are arbitrary arrests of citizens, especially in the south, as well as arbitrary searches of homes. Prolonged pretrial detention is a serious problem, and judicial corruption, inefficiency, and executive interference undermine due process. Freedom of speech, the press and religion are all restricted."
How can that be, if guns ensure freedom?
And that's wonderful! Hooray for them! Would that everyone be able to effect change nonviolently. Firearms are the recourse for when that proves impossible.
If they managed to do that in Stasi-controlled East-Germany, and in former USSR, it could be done just about everywhere.
And as I showed, there is no correlation between gun-ownership and freedom.