There was a mini-series called Jericho, which was about a coup in the USA. It began with a series of nuclear attacks on cities, and portrayed the resulting descent into inter-communal violence, gangsterism, shortages and hardship.

It wasn't anything like as scouring as Threads was. If anything it was more like a soap; they made rather light of nuclear winter and fallout.

I liked it, except the weak ending of the truncated second series.