How do you handle a disrespectful junior soldier that doesn't belong to you?

Are you sure he was a soldier and not, e.g., a paintball player?

Always have the Post SDNCO & MP Non-Emergency phone numbers on your phone. If the post SDNCO cannot get a hold of his Command call the MPs. They will restrain him until his Leadership shows up because he’s violating Article 91 UCMJ. While making phone call take pic of him with name tape in case they run. Or just call the MPs.

Likely stolen valor but you never know. Can you describe the patch he was wearing as it might not have even been Army as some of these stolen Valor douche nuggets are simply too stupid.

can you describe the patch

Take a picture? I would have call the cops have him detained under the general authority have the MP’s pick him up retain his ID and article 15 in progress

There is always the calling the MP's and let them deal with Soldier Billy Dumb A$$. The Picture is always an option. I suspect this person maybe a fraud?

This sure wasn't the military I was in from 59-66. Where has the respect gone. Rank doesn't seem to mean anything more. NCO,s don't seem to have any power anymore. If an Officer had been treated like that, Their would have been a court Martial and possibly brig time. If we got into trouble with another unit. Our 1st sgt. wanted the discipline to stay in the company. Usually Our ID cards would be taken and returned to the company with the infraction explained. I remember 1 sunday morning at camp lejune someone whistled at the Sgt. Majors Wife. from a barracks window. Every one in that barracks was disciplined. The duty NCO that sunday had to march us through 10 miles of the worst muddy trails with our combat gear on. When we were covered with mud from head to toe and our gear including our M1 rifles were full of mud the march was over. There were about 25 of us in the march. The only complaint I heard was" I hope she was good looking or I didn't even get to see what she looked like. Semper fi.

I'd say that you should just walk away and allow the young fool to continue f*cking up, sooner or later, that old Karma bulldog will bite him on the *ss.

He’s probably some YouTuber looking for a reaction to post online. You know he wants to be the next Roman Atwood.

When I was a Sgt E-4 I had an Airman coming on to some female Airmen under my care. I asked the Airman to leave and he responded "You aint nothing but a piddly assed buck Sgt so F$#K OFF". I promptly pulled my ID card and informed the Airman that he was under apprehension and I can and would use force to detain him. He attempted to leave I grabbed him and placed him in an arm lock and held him until the Security Cops arrived. He had been in trouble before and received an article 15 with loss of pay, reduction to Airman Basic E-1, and received an undesirable discharge. There are times when simple conversation or suggestion is not quite enough.