My two cents...
There are three atemi. The first is an end all atemi, knocking the person out and ending the threat. The second is a complimentary atemi, one that works in conjunction with a technique. The third is a combination of one and two. I don't want to hit the individual but I will if I have to. I throw the atemi with the same intent as the first, hoping my attacker will have the sense to respond to it so I don't actually have to connect, thus breaking the attacker's intended focus. If the attacker doesn't respond to the atemi as it moves toward its target then the attacker will certainly have to respond when my atemi reaches its destination.
Atemi are supposed to be used to allow you to take the mind of your attacker, so that you can hopefully offer a peacefully end to the situation. Sometimes this means hurting someone, sometimes though I find the best atemi is a kiss. Whatever takes the mind of my attacker is my atemi.
Lyle, hey nice thoughts. I like this concept, haven't really thought about it this way, but yea I think so!
So you can take the mind of your opponent either literally or figuratively/mentally!
And I certainly don't discount Mary's tactic as well. I think the concept of taking the mind to be very important to training!