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

Wear him out as you explain to the rest of the soldiers that the chain of command is not a fairy tale and you are not your own... you were bought with a price ,first by God and second, by your country.

That becomes their task every day.

We as soldiers enlist to receive duties from our commanders, to learn respect and proper etiquette of being an American Soldier. Sergeant did the right thing. Earn his respect from a lazy soldier.

Stand on his boots so he cannot back up get eye ball to eyeball ,& loudly congratulate him on being the First Shirts shit list!?

Smoke him

This has happened to me in the past. I had a new PV2 start complaining on the task i put him on. I looked at him and asked if he wanted my job instead. He said yes and for an entire day I made him the section sergeant. Needless to say with in about 3 hours he came up to me and didn't want it any more. Never had a problem after that. I was a section sergeant as an E5 and had this other E5 mouth off to me and when he did it it was in front of the Soldiers. I got pissed and lost it, being backed by the PSG and the 1SG I smoked him for 2 hours. All of the other NCOs saw it as well as the Soldiers and never had another problem. Different Soldiers respond differently.

Get a shovel and start digging a hole all day long!

Everyone is dismissed except the mouth and another soldier on either end of the barracks as a witness, Counseling, Article 15, Then a lawful order to clean the latrine with a toothbrush.

Corrective training or maybe peer pressure

If he's got the balls to stand up to an E5