Short story from the 80's about a strike team going through some tunnels with deadly traps

I'm trying to recall a short science fiction story, I think from the 80's.

It involved a military strike team, going through some tunnels/maze with deadly traps in each section which kill off various members of the team.

The very last guy arrives and talks to the person in the bunker who informs him he is his successor. I think they call this guy the, "Great Satan(?)". He basically suppresses the excessive military in the world, firing missiles if anyone steps out of line, aka, the sole superpower.

I was originally thinking it might be a John Varley story but it's not him.