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

Make a circle and see how tough the recruit is

Do NOT change the job assignment. The other troops need to know that, in the military, like it or not, you have the rank and you are in charge. There has to be a plan, beforehand, to handle this type of insubordination! Extra duty would be a good start. The chain of command should and must back you up on this. The alternative is a breakdown in authority. As far as the "shove it" goes, that's probably an Article 15 offense. Now we get into fine and loss of privilege!

When I joined-Drill Instructor put you down and punished the whole platoon and the platoon punished you in private---everyone got the message real quick-you are one!!!!!!

Smoke 'em all! The rest of the squad will make sure it doesn't happen again!

Whatever was needed to motivate his arrogant ass back in line to perform his duties without complaining and being a disrespectful shitbag.

slap him

Bring him to attention. Have 2 SNCO's Fall In alongside him and march him to the guard room to be charges with "Conduct Prejudicial to Good Order and Discipline"

discipline for disobeying an order

Kick his ass right then. I hit without thinking one time

As I have transitioned into federal service since separating, I still have had the privilege of working with some great military servicemen and women. So I have seen this occur more often than I wish to.

For every 500 or so terrific military folks I have encountered over the years, you occasionally get that one E1 or E2 that struts around the workplace acting as if there were four stars on his shoulder. The majority of NCOs that have been subjected to this insubordination from what I witnessed generally handle it in a proper and professional manner. When I see a junior enlisted military member "mouth off" to an NCO it does bother me to some degree. But I know it is not my place to say anything and the NCO usually takes care of the problem on the spot. In some cases I have seen the NCO use his/her chain of command wisely to have the insubordinate airman, soldier, sailor, etc reassigned to another office or duty.

Unfortunately there have been a couple of instances where a junior enlisted member has demonstrated has tried to assert authority over me by basically telling me how to to my job. First, I remind the individual that he/she needs to re-read the UCMJ and learn where their line of authority begins and ends. Second, I inform them of my civilian pay grade to state that I technically outrank them and to never address me in an unprofessional manner again. Third, I inform the insubordinate individual's direct military supervisor and let them handle it from there. Like I said, it's not my place to enforce discipline in these situations and I leave that to the proper personnel.

I know there are some instances where using the chain of command doesn't always work. But within a professional office environment such as mine, it is usually the best course of action for an NCO when dealing with an insubordinate E1, E2, etc. This route has generally yielded positive results in favor of the NCO.