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

Discipline, but Quickly, even If it's in front of the rest of my troops. Basically bring him Right back to their basic training days. Then, after the Alpha Charlie, a Huge write-up to go into his file, the reminder of his oath when he Volunteered for service to his country, and the orders he would obey from those of higher rank. If the situation further requires, send that E2 straight to the main office. This pretty much sidesteps my 3 strike rule, but I'd rather make it known to that individual, along with the rest of the formation that Any lack of respect, discipline, and responsibility for one's actions can, and Will result in consequences. No games, no backing off, period.

Smoke him

What to hear the 'Mom' or "DS Mode' response first?
Mom: Everyone, you know what I want-get it done. As for you, follow me and then he gets yelled at in private.

DS Mode. You have your orders of the day, PVT Shitbag and Squad leader, stand fast. All others, Dismissed. Then if you have seen Angry Cop/Angry Drill Sgt on YouTube, then you know he is going to get such a 'smoke session' and verbal lashing that even his great-grandchildren are going to feel it before they are born. But, seriously, I would be writing some serious paper on him, with the squad leader's help. Talking with his command chain and with them create some serious corrective training-the type of training that will not be humiliation, but teach respect.

A lawful order needs to be followed. Start the process immediately to either get that rolling or get them rolling out, often with some extra "fun time" like corrective custody. I had a "request" to run corrective custody to which I said no thanks. Since a request and not an order felt I was within my rights (as limited as they are in the military). To which it was mentioned how would you like to be in corrective custody? So you want to put me in jail for not wanting to run your jail? And why I am a civilian where that logic I can move on from if an employer tries it. You do not have that option in the military. At least not if you do not want a big negative mark on your discharge.

I’m amazed the cuestión is even asked! Who’s in charge!? I like to believe someone handled it.

The monster emerges and life as he knew it is about to change. Everyday he is there

Dismiss everyone else...invite the young lad to step inside the barracks...thump the living shit out of young blood thus realigning his military compass...make sure the lad gets in one punch such that you can claim 1) self defense 2) charge him with conduct unbecoming 3) insubordination to a Staff NCO 4) call his parents letting them know junior will be home this weekend 5) call the MPs and 6) notify the platoon commander or appropriate CO so the facts of the case do not become cloudy over time.

PV2 is about to have a long day. Immediately after formation , PV2 and squad leader will stand fast . I will make an example of him and squad leader, the squad leader for allowing and letting this happen and PV2 for the action

1st of all, all the NCO’s in my unit would be all over him before I could even react, so when you ask me what I would do, sit back and enjoy the show.

I’ve trained my NCO’s on the proper way they as NCO’s should act, disrespectful actions to officers or NCO’s will be handled quickly and aggressively.
We as leaders set the standards for lower enlisted to follow.

AATW

Also, you might let them know that you are not a oc fresh out of college.. I know in the army I had a special forces DS and he told us to basically give no fucks about ocs guys

Or write them up for "failure to adapt".. I was a ass my beginning years but I did my job.. but I had reason, I was literally the minority and constantly picked on.. lol I threatened my E-5 to kick his ass.. away from the platoon.. and that was the end of that.. I went on for ten years with no hickups.. just one dick E-5.. so think about your soldier.. try to figure out his problem and if he's just worthless.. article 15 failure to adapt

With today's rules... I'd say mass punishment.. let his friends get pissed and do the dirty work that you can't. Lol ever had soldiers doing push-ups, feet on a lmtv front bumper.. very effective

Myself a former USAF sergeant, air/ground crew rigger. 1964-10/1967 stateside...S.E. Asia 10/1967-10/1968, then my DD-214.
How WE did it...
First, the entire training squad is informed of DIPSHITS transgression, and need for an "attituse adjustment".
Then the squad gets "shit duty"...picking up, field stripping (separating the paper, tobacco, and filter if any) from the tossed cigarette butts from a LARGE area, OR...dandelion picking from a likewise large area, you get the idea.

Typically in turn, DIPSHIT gets a "blanket party" in the middle of the night, maybe the same night or relatively soon thereafter, as a "thank you" from the squad members he screwed with.

THIS...always corrected a DIPSHIT'S attitude...

How would I react?

NOT WELL AT ALL.

First and foremost. The issues here is obvious. #1, Respect & #2 Discipline.

Any one of my soldiers knew the ramifications of what would happen. And they would never would of acted out like that.

Getting to the issue, Pvt Loudmouth would of paid dearly. The next step would be standing on the carpet in front of the CO and receive punishment under the UCMJ. If it continues, then there are several ways to reach that soldiers attention. Peer pressure is one. Wall to Wall counseling, though illegal, is another way. Ultimately, the discipline issue can lead to dismissal from the Army. I never tolerated that behavior. Because my soldiers knew that I had zero tolerance for BS. And if left up to me, that soldier would regret ever doing it. And it would never happened again.

As a respectful E-5, I'd probably think about the E-2 response for a few seconds then I'd dismiss the platoon - except for the E-2 - and then I'd probably "shove it" somewhere the idiot E-2 wasn't expecting it to be shoved.

Lol when I first read this I immediately thought of a famous line in a movie, “I want him spitting blood.” Just recall a version of the same comment made to me in the military, “it ain’t training till your spitting blood.”

If I was an NCO life would become very difficult for that E2. Document and discipline until he or she developed military bearing or was out the door to civilian life. The choice is the soldiers in the end. One thing that helped me adjust in the military was telling myself “the NCO is not the enemy unless you make them the enemy.”

I would have Sergeant Major and myself discipline the young soldier, after explaining to him the code of conduct and after training there would be more training with the head NCO observing progress.

Pvt shitbird would be making the walls sweat after I got done with him for pulling a stunt like that.