Same playbook as Chechnya & Crimea, Russia Militia's arm the citizenry to defend themselves.
BTW, Putin refers to Russia Militia as "little green men" in a 2015 interview concerning Crimea.
Before annexing Crimea, his Army had already infiltrated the Country, armed citizens to defend themselves. He calls the U.S. "Nationalist Puppets" & conducted secret polling prior to going into Crimea.
Don't forget he found a crashed submarine off the coast of Crimea after annexation.
He's on top of this.
I'd bet the 40 miles of troops are preventing someone/something from leaving, or we are being shown false video. I cannot find his documentary Crimea: Return to the Motherland.