Iran was our closest ally in the region for 25 years and we didn't know jack shit about it. My bet is the only nation that will understand Afghanistan is India, and they'll be very stingy with information.
We didn't know jack shit about them because we didn't attempt to learn. Since the Communists are all about increasing the world's living standards, it would make sense that they would learn more about their allies to ease the process.
The only reason the Comintern would lose in Afghanistan is because the majority of the populace literally live like hermits and are completely opposed to any ideology that wasn't created in the first millennium.
I dont see why Kabul wouldn't possibly become a Commune though. The Reds might lose, but they might keep it as a way of saying "we didn't get knocked out" while the Alliance would probably only smuggle in weapons for as long as the Reds were pumping out divisions into Kandahar.
Other than that sweet Afghan Kush I don't see the Allies wanting to get too involved. The Franco British have bigger problems in Eastern Europe and the Indians, if they're smart, will just give them weapons and wash their hands of the situation.