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

i don't believe I asked what he wanted to do. He will do it or face consequences! Stand your command.

If you are in the Marines, that is considered a direct order. Follow it or suffer the repercussions. But if you are in the guard or army, you must sit and counsel him and give him another chance.....poor me. In the old core use descussed it quickly out back and they see it your way

Have him and his immediate supervisor stand-by until all other assignments are handed out, then have the two waiting made aware of the infraction of the Pvt, and that his disobedience, and insubordination will not be tolerated, and the assignment will be completed. If the actions are repeated, the matter will be referred up the chain for disciplinary action, i.e. Article 15, or worse

PT the shyte outta him.

Tell him to get ready to see the old man. Will recommend 30 days restriction, 30 days extra duty.

Praise in public, Reprimand in private.
Make this an issue that is TO BE DETERMINED.
Make sure the subservient KNOW this.
Follow through in a VERY timely fashion.

Post the rest of your command. Hold the dipstick until others have go on to their assignments. Inform him that he is expected to obey a lawful command and that nothing else is acceptable. And that refusing to obey a lawful order will shorten his military carer to a few more miserable weeks. If that is what he wants, he can be accommodated, else get his butt out and do his assignment.
Then look at what made him think he can get away with his behavior, and correct it fast.

I don't know what years you did service but in my day PFC would be looking up from the ground on his back,LEARN RESPECT THE HARD WAY!!!!!!!!!!!!!

Drop and do push ups till I'm tired soldier.

Call to office for talk about insubordination charges. Or derolection of duty