In 1985, instead of Gorbatschov, a militarist gets in charge. He does a few market reforms (NEP3) and, unlike Gorbatchov, succeeds, achieving high economic growth rates, even higher military production growth, and an increase of the speed of technological development. A lot of secret weapons and defenses are put in place.
The rebels in Afghanistan are put down with brute force and by relocating nearly all the population into the larger cities, so that they can more easily be controlled. In similar ways, unrest is quelled in more or less communist countries all over the world, while more and more countries with high numbers of unhappy people are driven towards communism by sponsoring resistance there.
As can be imagined, western nations aren't too happy about all this. So tensions are at an all-time high.
In 1988, the SU decides to conquer Europe in one big surprise attack. The official reason is breaking of treaties concerning ABMs by the US and having to do something against this. At the same time, they secretely supply practically every communist and even some non-communist but anti-western resistance group with a lot of weapons and guerilla warfare information.
Therefore, the US is pretty busy in Latin America. Half of Europe is overrun quickly. Japan turns her productive capacities towards weapons, but is too weak to attack Russia at that time. North Korea attacks South Korea, and some more wars start all over the world.
The advance of the communists can be stopped, though, so that no nuclear weapons are used.
I happen to end up in a communist occupied area. Not being religious even opens some doors for me. So I see first hand what's going on behind the scenes - deportation of any opposition into pretty deadly prisons, masses of people turned into wrecks by intense interrogation, and other forms of suppression. My sometimes very little respect for popular opinions and equally little talent for phrasing things the way my surroundings like it gets me into a situation where I know I might be next on the list. Furthermore, I happen to become witness of some military unit putting down minor resistance in a very brutal way. I decide to not try adapting anymore and flee the occupied area, not before taking a few secrets with me - tactics, weaknesses, plans, and so on, partly from simple observation, partly from "finding" information in the offices of people I happen to deal with.
I find a small group of a few hundred soldiers on the western side of the war torn area between the blocks. I show them the side I'm on by giving them my informations and proove it by participating in an ambush and making the first shots. After the first Soviets are dead and the rest of the force does the rest, they like me and I become soldier in their ranks.
In the curse of the war, I even happen to save my group once by spotting hidden enemies trying to ambush us.
One of our assaults doesn't work out that well, so I get shot in an arm. That earns me an instant medal, I become a war "hero". The press puts a picture of me in a newspaper (not many buy that edition). Also, there is nearly always a nice welcoming parade whenever we manage to liberate a city.
After some time, the Soviets are back in their old countries (I'm simplifying a little) and don't call themselves Soviets anymore. Due to an astonishing recovery between 1992 and 2005, everything is now nearly as in OTL again...
