They knew it was the village. They knew there were Taliban there shooting on US and Afghan forces. They didn't know where the civilians were - because when there is shooting going around, civilians hide and it is very hard to see if there are any around, and how many of them, especially when you're being shot at at the same time. So they called an airstrike, and that turned out to be a big mistake. They could suspect that there might be civilians - since among Taliban, just like similar groups like Hamas or Hesbollah - hiding among civilians and using them as a cover is a common tactic, and since it is a village after all - but they did not know where, how many, etc. After many hours of fighting against hundreds of Taliban and after suffering casualties, the people on the ground made decision to call in air strike. Unfortunately, that resulted in tragedy, since the places where airstrikes were asked (presumably where Taliban forces were concentrated) turned out to be at or near the same places where the civilians hid. If the US soldiers on the ground knew that, they probably could do something else, but I don't see how they had to know it in the heat of the battle.
> By the way, it's a really crappy air force that can't do an air strike with sleeping-gas bombs.
I daresay that would be a lot less effective than you might expect. See the Moscow theater hostage situation[1][2] for what happens when trying to use it on a fixed target with ground level access. Imagine how much harder that would be from an air-drop, and the concentration gradient you'd end up with. Individual dispensers, cluster-bomb style might help a bit, but I still think you'd end up killing anyone close-by if you wanted it strong enough to permeate buildings.
Calling in a heavy smoke/CS drop and then retreating might be a sensible option, although I don't think there's nearly enough (public) information for anyone to judge definitively on the correct course of action in this instance.
The Moscow situation is not comparable to Afghan countryside.
If "effective" includes "not killing innocent civilians" then sleeping gas would work much better than what they are dropping now.
If smoke or CS would work better, well it's the military's responsibility, not mine, to the the R&D to pick the right tool to protect civilians as required by law.
> The Moscow situation is not comparable to Afghan countryside.
Precisely. If anything, it's a much more easily controlled environment for gas diffusion, and allowed almost immediate entry by the special forces to clear the area. Even then, there were significant hostage fatalities (although in a large part due to medical staff not being timely informed of the nature of the gas, or provided with the antidote)
Achieving that level of consistency of dose (enough to work, not enough to kill) in a rural village environment, via air-dropped containers, is, IMO, utterly impossible.
I'm arguing against your suggestion of 'sleeping gas bombs' only, not that the indiscriminate bombing is/was the correct choice.
In addition, R&D only determines what you will have available maybe some time in the future. If you're in combat right now, you don't have the luxury of waiting 3-5 years for promising test-bench stuff to make it to your rucksack/support units.
If all you have is high-explosives, eventually everything looks like rubble.
If "effective" includes only "not killing civilians", opening a hot dog stand nearby would work as well. However, if it also includes "stop 400 Taliban fighters from shooting at us", the situation become a bit more complex. Smoke would just remove visibility. But Taliban don't need much visibility - they already know where the forces are, they were fighting for the whole day in the same setting, and they probably know the village inside out anyway. And they also don't care if they hit a civilian by mistake, so they can just keep shooting in general direction. And if you use some real active chemistry, the civilians - especially children - would be the ones hit the worst.
They don't have phasers that can be set on stun either.
There are chemicals, of course, that can cause loss of consciousness, but any that causes loss long enough to be effective against the force of 400 people hiding in urban setting, would kill most of the civilians. It's not random that when the human is anesthetized it is done in controlled setting by an experienced doctor with very precise mixture of chemicals - it is very dangerous to do it and exceeding dosage could be lethal or cause permanent harm. Military weapon can not adhere to such dose requirements so it will be either ineffective or extremely dangerous.
This was the easiest setting - everybody in one enclosed building and civilians can be treated within minutes after the attack is done. Imagine doing this in a complex urban setting, with multiple buildings, with 10 times as much enemies, where both enemy and civilians can be anywhere. It's just impossible to do without killing everybody and leaving the place a chemical wasteland.
And, of course, on top of that, if US military does it once, Talibans get gas masks. But civilians would not, so the only effect would be killing civilians.
http://www.nytimes.com/2009/05/15/world/asia/15farah.html