A sudden out of the blue nuclear attack is in my opinion rather implausible, since signs would be pickd up beforehand and since the Soviets were not as crazy as some think.
The doomsday scenario on the Wiki is in my opinion a lot of rubbish, since it contradicts itself many times and simply does not make sense upon closer inspection or scrutiny.
I have said a few times what I believe the Protect and Survive world of 2011 will look like. It will be very grim and very poor that's for sure, but it won't end per se and as long as command and control survive to an extent, nations should be able to survive and not fall apart. Once basic infrastructure has been rebuilt to a usable degree, reconstruction and recovery should be rather fast in my opinions in countries were control and command still stands. It has been proven time and tile again that mankind is a resilient beast and that country can rise again from the ashes even after having been apparently completely destroyed. It will take longer for this to firmly kick start and happen following a nuclear war, but after five or ten years I firmly believe that it will happen. Living standards will be lower than what they once were for probabbly half a century, but people don't need a television, a car, a game console, or a computer to live and thrive!
The thing is that despite what some say and some like to think. A nuclear war is very much survivable and even dare I say winnable, provided that nations take the appropriate measures and ensure that their fabric bends but does not break post strike.
Now if course I am of the opinion that the best protection against nuclear war is
this or worldwide disarmament.