How many times has Afghanistan seen off the army of a foreign nation?

I'm watching a documentary on it now - it's interesting, at one point the member of the Afghan royal family says "I was once visited by a businessman from a US company who told me he had access to a billion dollars to invest in Afghanistan. He didn't understand. Afghanistan would rather live in poverty but free, than be rich." These people seem to have decided they would rather fight to the death, in accordance to their beliefs, than accept foreign rule and influence.

They seem to have paid with their lives, mired themselves in war and poverty and technological stagnation, and yet there is a sense they would have it no other way.

@plungesponge: But they are fighting amongst themselves

Yes, that feudalism is also in accordance with their beliefs.