I don't think you will find the 1984 setting much of a distraction, and sadly so, the geopolitical squabble that escalates into war is pretty well still relevant. You might have to strain a bit to catch all the dialogue if you're ear isn't tuned well into Britspeak, but it's worth the effort.
GoogleVideo has the whole movie available on their website for viewing here. It's also interesting to check out the Amazon listing for the DVD of the movie to read the recollections of many British viewers who were profoundly affected by this TV movie when they originally saw it and still retain vivid memories of it, disturbing memories which none of them regret having.
A few years before Threads, Mick Jackson directed a documentary for Britain's QED showcase (kind of like our NOVA on PBS) called A Guide to Armageddon, about a nuclear bomb detonating above London. It's available in three parts on YouTube, and I also highly recommend taking a look at this. It's not really the kind of show one would embed lightly, so we're going to make you go to YouTube to watch it.
Why am I doing this to you? To make you ponder, that's all...and to see some really amazing television.