I didn't really get into Half-Life until recently, after September 11th. So I am seeing the original game with a new perspective.

It's difficult to imagine that the original HL had the player killing U.S. Marines. I used to think that the only acceptable video game enemies are mutants, aliens from another planet, mercenaries, mobsters, or Nazi's. Now, I guess you can add pedophiles to the list of deplorable and acceptable things to slaughter in the virtual world, but Marines? They're not even mutated, like the ones from Doom.

Of course, this is impossible for HL2, so Valve invented Combines. It's acceptable to mutilate them because they're not even fully human.

I think difference between U.S. Marines and Nazi soldiers is that there is no systematic campaign endorsed by the soldiers to eliminate and torture civilians. True, Marines have committed atrocities, but at least it's not tolerated by the masses and endorsed by the government officially.

German soldiers could have refused orders to murder civilians, yet they just went along with it. If they truly believed what they were doing is the right thing to do, then I have nothing more to say.

But it's true that if Valve released HL2 with Marines being the enemy again, they might be black-listed by the FBI as a possible terrorist cell.