I don't see it as a problem. War games don't transfer to real world violence, anymore than street racing games translate to real world dangerous driving.
I remember when I played need for speed most wanted for the first time and they had the main actress in the opening cutscene to the game telling you that... this is all just a game and in real streets you should drive safely and responsibly and wear your seatbelts. I never skipped the cutscene because Josie Maran (the actress) is really really pretty, but the message is absolutely and unimaginebly dumb.
You're sitting in front of your computer manipulating a car through an interface that doesn't look remotely like the controls of any real car, "driving" through a world with bizarre physics and collision logic with zero haptic feedback, again, an experience unlike any in a real car. Does any reasonably intelligent person really need an actress telling them that "remember, this is all just a game" ? isn't it all kinda obvious ? would a person who somehow got the idea that real driving is as easy as mashing some buttons on a keyboard with zero consequences be snapped back to reality by a character inside the game telling them that it's not true ?
The only real way I can see a "fiction leads to the real thing" argument working is through propaganda, a military might invest in war movies and war games to make it look glamorous to a gullible teenager who will be of military age soon. But how can you prevent that without demonizing all fiction ? Before video games, before movies, before even reading and writing, the military had no problems whatsoever with getting recruits. Propaganda is just the symptoms, the real problems are all downstream.