Lester, TESTAMENT is a real emotional punch in the gut. Carefully drawn out in slow heart-wrenchingly believable steps, it does with dialogue driven simplicity what many nuke films can't do with two hours of explosions and vaporizations.
Russell Mulcahy's 2000 Aussie remake of
ON THE BEACH for Showtime is also quite effective. Having the main Australian characters played by, well, Australians goes a long way towards making the whole enterprise work. Even with the numerous times I've watched it, the final ten minutes still evoke a strong reaction from me.
I also strongly recommend BY
BY DAWN'S EARLY LIGHT. I'm sure I may have pushed this one here before, but it is a superb thriller concerning the first 12 hours of an escalating nuclear war between Russia and the United States. Told from the point of view of a B-52 crew on their way to Russia, the command planes roaming the American skies, the President and his mistakenly installed hawkish successor, this HBO film from 1990 ratchets up the tension relentlessly as the command and control structure of the American forces falls apart under the strain.
You may be able to spot THREADS on youtube. Every so often someone posts it there in multiple segments. If you can though, don't watch it that way. If you need, let me know and I'm sure I could get it to you somehow. Along with that one, you should check out Peter Watkins
THE WAR GAME from 1965. It's cut from the same cloth as THREADS. Very well made and downright chilling, the BBC refused to even air the thing, despite having produced it.