I don't see anything saying the enemy is using US provided stinger missiles against US aircraft. There was a report of "smoke trail", which may or may not be accurate. If accurate, I would assume it's a soviet weapon (SA-7 or successor), or maybe a Pakistani stinger clone, but very unlikely a US stinger given in the early 1980s.
Yes, a lot of this is interesting, but isn't far beyond that is available in the news, at least if you have a basic understanding of military operations in Afghanistan. If you read 2-3 of the popular military blogs (Michael Yon, especially), you would know 95+% of this.
Unlikelier considering the Stinger is filled with oddball proprietary batteries, and a canister of argon (for cooling the seeker head right before launch) that I've been told leaks over time.
That's true, but depot-level maintenance could certainly deal with that. Taliban in caves in Afghanistan probably not, but ISI/AQ Khan organizations in Pakistan are fairly sophisticated (they built nuclear weapons, after all).
More unlikely because the stingers given to the ISI/Afghans were early models with less effective seekers (more easily jammed) than the missiles available today from other sources. Current generation Stingers are the best, but current missiles from China, Russia, etc. are probably superior to first generation Stingers, especially ones that have been carted around Afghanistan.
US military helicopters and other aircraft have a variety of countermeasures -- electronic systems, well chosen flight paths, low altitude operations, and multi-ship operations (where one helicopter supports another), plus support from other aircraft for ECM. Compared to a commercial airliner, they're non-trivial to shoot down. There are plenty of contractor/NGO/etc. operated Mi-8s and other crappy ex-Soviet helicopters flying, but those crash on their own quite frequently -- no one needs to shoot them down.
There was a period where people were really scared that stingers would wind up in the hands of international terrorists who would shoot down a commercial airliner in the civilized world. There was a huge CIA buyback program for these weapons; during the Afghan civil war, they were actually too expensive to expend, and were mainly just kept by various leaders as totems of power.
I really doubt US stingers are being used to shoot down US military aircraft in Afghanistan. I admit I'm fairly biased on this, being a frequent passenger, but I'm pretty sure small arms fire and RPGs (unguided rockets) are still the primary threats.
The countermeasures don't reduce the chance of hit manyfold, certainly less than twice. Jamming is useless against heat-seeking heads, and flares help only so much.
It's pretty certain stingers can be, and probably were used to attack NATO aircraft, successfully or not. Stinger specimen were found as late as in early 2000s in Chechnya, showing there's still quite a few in circulation.
AN/ALQ-144A and AN/ALQ-157M is an IR jammer, and effective against IR MANPADS. The newest Stingers are IR + UV to defeat this. This is the "disco ball".
I don't know how effective these are (I suspect the primary defense is route planning and flying low/fast), and no one who actually knows the effectiveness would be able to comment.
Yes, a lot of this is interesting, but isn't far beyond that is available in the news, at least if you have a basic understanding of military operations in Afghanistan. If you read 2-3 of the popular military blogs (Michael Yon, especially), you would know 95+% of this.