What concrete steps do you think the U.S. should take, other than talk?
There's nothing the U.S. can do, other than talk. And hopefully remember that there are people in this part of the world who don't like Russians.
Nobody is asking for foreign military intervention.
What’s being asked is to deny travelling visas (done) and impose economic sanctions on government officials who authorized the police crackdown 3 months ago and had sanctioned kidnappings/beatings/murders that took place ever since.
Freeze their assets to hurt them where it hurts.