We can no longer assign a country or even a ideology as an enemy. So when TV and Movie execs want to make a war type movie, they place Zombies in the place of the nazi's, commies, or pick your country, ethnic group of choice to fight.
Not like in the days of Rat Patrol, Combat, the Big Picture, Mr. Roberts.
Same thing with the alien movies a couple of years ago. I wonder why these stopped? Did we get a complaint from Venus?