I'm talking about if the US already was at war with them and hitting them hard. I don't see what would restrain them at that point.
War is not a game where each side gradually loses their “restraint”. Instead, each side carefully considers each possible action and its consequences, and then does whatever action seems to lead to the best end result.
Yes, the do that when their enemies are individual people, since that tactic works on those. I doubt the same tactics would work on armies or nation states.
> so they can watch those people die in a gas cloud.
You still seem to think that the cartels do things merely for their own cruel amusement. I, on the other hand, believe that cruel amusement is luxury which they allow themselves only as long as it works.
I agree with you on this. I also think it would absolutely work, just like it works in Mexico. I also think it would be the first choice of people accustomed to it working.
I feel that the U.S. Army would not respond favorably to terrorism.
> I also think it would be the first choice of people accustomed to it working.
Well, that may be true; they might be stupid enough to do that. I couldn’t really say; I’m just a random person on the internet without any special knowledge of their psychology.