In the novelization of the miniseries, the final scene
has Caffey and Vorashin shaking hands on the battlefield as US and Soviet missiles pass overhead on the way to their targets
.
So, I believe that Vorashin (in the final filmed version) was being genuine with Caffey. Some of the earlier dialogue between Vorashin and the political officer also supports this. It makes for a much more interesting twist and anti-war statement - that two soldiers on the field can come to a peace while their leaders could not.

When I first saw the movie, I thought that Vorashin was in on the trick (the tossing of the grenade). But recently it occurred to me that since the Russians had complete control of the valve station, there was no need for him to die if he was loyal to the missionhe did get killed after all.

The paperback novelization of this miniseries evidently was working from a much earlier draft of the script that in the end had a more tragic finish. In it, Caffey's band actually turns things around and fights the Soviet group off, but in the end, because of a communications failure they are unable to get word to Washington that the Soviet force has been defeated, and thus McKenna and Gorny (who is NOT killed by the KGB but is still being manipulated them) end up going over the edge because they operate from the mistaken belief that the Soviets hold the pipeline.

He was duped also. I feel the one who thru the grenade was the political officer. Kinda like Putin today.