How would you react to an E2 who "smart mouths" you in formation?

This a simple answer. You give him the worse assignment. Then you ask him to remain after formation. This is a teachable moment for him. Remember some people want to be in charge but do not know how to do it. If he is teachable then you get him on the program. Remember when you know who you are barking dogs do not bother you. And you always have Tops to bag you up!

Article 15 for insubordination.

Well, my first impression as a mother is to slap the holy hell out of the little snotbag. But. Hmm. I'm pretty sure that's the wrong answer. And, I finished out as an A1C, (got out when pregnant, back in the later 1980s) so I didn't take NCO leadership classes. And, besides, Lol. I seem to have a little bit of a temper. Which I DO control pretty well. Mostly. The correct answer is that you take the little darling and his supervisor to a quiet place or make the place you are at more private by sending everyone else away. You inform the little darling that this is not his Mama's house, nor is it a democracy. He has not been promoted to General, either. How he believes this after Basic Training, is anyone else's guess. Usually those problems are taken care of there. You can point out to your insubordinate little trooper that he has broken military law, and is behaving in a manner unbecoming, as well as having terrible military bearing. And, gee, isn't it just TOO BAD that he signed that enlistment contract, NOT UNDER DURESS, therefore he has already agreed to follow all lawful orders, and this is one of them. Should he choose at this point to be difficult and not obey the order, there will be consequences. Serious consequences. It reflects poorly on the supervisor, and he will be dragged down with the little snotbag. (You probably shouldn't CALL HIM a little snotbag to his face. That's for later on.) You have the right to punish him for insubordination, and perhaps you should, by writing paperwork, and I'm sure the supervisor will be happy to find some unpleasant little chores for him to do, also.

As a Midshipman at USNA in the 60's, there was a Plebe who had done something wrong and was stopped by the Midshipman Officer of the Watch (MOOW). The MOOW was a senior nearing graduation. They (the Plebe, the MOOW, and the MOOW's orderly, another Plebe MOD) were all wearing Tropical White Long uniform. They all wore shoulder boards. The MOOW began chewing out the Plebe something fierce while the plebe stood rigidly at attention in a brace. Finally, the Plebe reached over to the MOOW, quickly unsnapped, removed and held the MOOW's shoulder board to his head like a telephone and shouted into it "Beam me up Scotty, it's getting hot down here!".

You must be in one hell of a piss poor unit , in my day (age showing over 60) the other privates standing on either side of him would take care of him for his behavior , if you pissed off a NCO and you were a private and did it in formation you were going to get a complete ass rearrangement , no one wanted the kind of heat that would result from not only this NCO but every other one in the unit.
Heaven help this fuck wad if this was an active combat forward area , he might not make it out with all that he entered with if you get the drift. Has the military become such Pussies this would ever happen , if so lord save us when the next load hits the fan ..... Glad i'm not you , one of my troops did that , the MP's would hall his ass to the stockade wile formation was still on so the other troops could see , if the CO was feeling extra kind that day the private would get sent to "Retraining Platoon " at the fort stockade ... think "BUDS" hell week , but no swimming for 90 days instead of just confinement and dishonorably discharge.

Been there done that . Flat out this type of behavior tends to be very contagious if not zeroed out at light speed . I joined when Ford was president and then got Mr. Jimmy Carter's fun rein soon after , military moral and discipline was a very strange animal during those years . There were officers and NCO's who were just marking time to retire and those who were all gung ho and the one's who knew their jobs and did them to the very best of their ability's without being screaming mimi's or overly harsh in their bearing . That being said I was lucky for the most part having true professionals to learn from ( Still had some of the others as well but not many ) . One thing I learned was that yelling and screaming in front of the platoon at an individual tended to have a negative effect on the troops ( Except for when I was a D.I. ) BUT ordering them to stand fast while dismissing the remainder of them to their duties was something that the men who had been serving under me understood was not something that you wanted to have happen . Depending on how loud and or vociferous the troop was while " debating " my orders set the manner to which I proceeded with correcting said troop's reminder of the fact that they were in the military and subject to not only the UCMJ but to the platoon / company and battalion he was serving in . I'd keep said troop cooling his heels while I had a discussion with his squad leader ( as his squad leader he would have more recent background info about him than I would ) after that I would proceed with the troopers attitude adjustment . It was always made very clear to them that there was NO place for any action other then compliance with lawful orders ....At this point in time things could go " MANY " different directions as people do tend to act different , if said troop was amenable to moderate discipline and correction of his negative attitude then things were kept to the minimum necessary . However I did have some who required harsher means of correction ( I always regretted having to up the ante as I felt it reflected on my leadership skills in a negative manner , personally as well as militarily ) . I had two who required artical 15's to get the message across , both times I had to have the LONG discussion with Top and the Co. commander ( Never fun ) ! I reckon that the point I'm trying to make here after being so long winded is that this type of behavior MUST be nipped in the bud immediately as well as taking the time reflect on how you personally could have done things better to avoid this from even happening in the first place . Simply reacting without thought will almost always lead to more trouble down the line in my experience . I've never understood how people who " JOIN " the military can feel they don't have to follow lawful orders if they're not in the mood , and or how they got through boot camp and AIT without this attitude being dealt with before they ever reached their permanent unit .

I don't know the gravity of the situation. I would start with counseling telling service member and give extra duty. If this continue, demotion is sure. Tell him if you want to serve well, you don't want a black mark in your record because it will harm your service. Sometimes, strong will person if get directed to a right direction they can excel well.

Not very well.

Of course that was back in the "Old Corps"! Just the same, you do what you have to do, to get the job done!

I can only say that, in the Marines, that kind of shit is often times taken care of by that individual's barracks mates! I remember an instance where we were unloading the trucks after a 30 day trip to the field and one of my men was slacking off. I was in no mood for his shit and offered to take him out behind the Comm. shack. Never had any more problems with that individual!