you can't generally reason with a two or three year old - as a pp said, a slap or tap (NOT "hit")
It's hitting, and there's a reason you don't want to call it that. Ever thought that what feels like a "tap" to you feels like a "hit" to a tiny child? And no, damn right you can't reason with them, and that's exactly why you shouldn't be hitting them either. The only thing they'll understand is that you hit them. Like I said, I can't remember why I was hit, but damn I remember that I was hit.
it would be a parent's terrified response if this had already happened, in the hope that the child would know not to do it again.
I thought you said you couldn't reason with the child? So how will they know what they were hit for and what not to do again? If they were able to pick up on your shouts, angry and distressed tone and negative reaction and associate that with the action, what will hitting them add to the mix that is so crucial and otherwise absent?
And why are you so anxious to stress the parent's "terror" as a mitigating factor? Because you think hitting children is more OK when the parent is in a state of high tension than when they're not? In other words, it's more acceptable to hit your kids if you're "losing control" which, by the way, is exactly the justification used by your common garden variety abuser? So it's not actually entirely about safety or correction, but at least in part about not controlling yourself?
I agree this could be a problem when they're playing with other small children, it would be harder to enforce the rule of "no hitting"
No shit, Sherlock. Unfortunately, when you make it ok to hit children, you may find it hard to explain why it's not actually OK to hit children.