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

im retired but it was never a good thing to smart mouth in formation. mostly just run until they puked

Have a tornado party and let the rest of the platoon take care of him with a blanket party.

Plain and simple he has no choice but to obey a direct order. If he fails to comply not only will he suffer the consequences but the group will, will lack of freedoms. It will get solved right quick.

Head spin to private...laser eyes of death. "Private? Did I hear a No?", "Platoon, did that private verbalized a No, to me?". Yes Sergeant! Well, well. A damn conundrum here ladies. "NCO's front and center." "Private please join us at your convenience...'smirk'. "Private, you are going to lead the platoon today in some strenuous exercise designed to make us all better soldiers followed by your assigned duties." "You private will not participate. You will simply supervise."

Teaching moments ladies and gents. It's all about those teaching moments. Just like a good crisis, never let it go to waste.

Followed up by witnessed counseling and motivational speaking engagements together.

I tend to try and leave the brass, article 15's, etc out unless it's a repetive issue.

Having been a Sgt in the Corps and now 10 years as a juvenile probation officer and supervisor, I handle these situations much better. 1st isolate the negative impact on others, this is toxic to the team environment. 2nd remain calm, but commanding, fair and instructive in your presence maintain your position of leadership (lead from the front not your rear), instruct clear expectations and options to resolve conflict, not based on your opinion of the person, but from Corps Values (this is objective, principle based, and non judgemental, maintains the position of authority and leadership so you're not a hypocrite later when you screw up), learn about the Marine show genuine interest in why they are taking this position and what they are wanting, formulate a plan to achieve overall objective of the unit, leadership and their development. Do it in private so you're less likely to get blow back if they become defensive and attack (Marines don't usually flight, they fight). This will likely do nothing more than undermine your authority and position of leadership to the unit. You will be out of control. I've personally experienced this as a young Sgt., it's not good. If they are not amenable to redirection, move forward with your tools of redirection. All of this can be accomplished while maintaining Corps Values, tradition, maintain and build Esprit de Corps. It doesn't make you weak. The unit doesn't need to see what happens, they just need to know you are consistent, fair, firm all qualities if a great leader. They know, despite best efforts, some people are of poor quality. That person will either redirect, become rejected by the fold or ultimately released from their enlistment. Semper Fi.

Front leaning rest until I got tired!

It's an issue that needs to be addressed right away. Of course, you could put said PFC in his place right then and there but then you are going to be that leader. The kind that has to lead with fear and public punishment. I'd say, have him standby. Ask him what's going on? Not to avoid punishment but to figure out whether he is having a rough day or he os just a disrespectful punk who thinks he rates. Then, take him out and run him into the dirt. Train him to push physically and mentally. Explain to him, "you know, I understand you might be going something, but I can't let you pull that stuff in front of everyone else and set a poor example. I'm going to have to do something." Make him burn all of his aggression out until he earns his discipline. Make it a learning experience. Learn what he can take physically and what he can take mentally. Make a teamwork exercise. Make everything he does require that it takes two so that he can learn the respect of a leader and his subordinate. Teach him that you are his leader and when he feels like giving in, you are going to be there to lead him to the finish. You are going to expect more from him and you aren't going to allow him to do any less than the best that he can. Then have a counseling ready for him. After you are done bettering him, talk to him. Let him know that you have no hard feelings and that this is a chance for him to better himself and be a leader amongst his peers. Let him know that this is just another day and tomorrow, is a brand new day; you aren't going to hold a grudge against him. Remind him that you are there for him and that it's nothing personal. "Think of this as an opportunity to train and move forward. Never look backwards from here. Keep movin. You are a marine, remember that. Keep that title you earned. Every day you are out here, you are earning that EGA on your chest." Then move on. Let him demonstrate whether or not he needs further adjustment. If he is just a bad seed with a piss poor attitude, he is going to get himself kicked out eventually and there is nothing you can do to stop that. Be the leader that gives him the opportunity to change how other marines see him.

Just apply UCMJ, if it doesn't work, repeat and if not jailtime and a dishonor discharge. Since we started to be politicaly correct this military started going down hill...

Get him or her to the side and counsel them on where they were out of line and to be advised that they were going to be an E1 again.

Been there, done that. I have sharply reminded them that they are an E-2 in the United States Army and I am an E-5. They'll do the assignment and keep their mouth shut about of the UCMJ will apply. "You can do the assignment or be charged with an Article-15". Then he'll be an E-1, lose half a months pay and I'll have him for 14 days extra duty in the evenings. No big deal.