If the FEV virus didn't exist?

[The-Artist-64]

From my understanding, no FEV would mean no Brotherhood of Steel, as the US Army Captain (I forget his name) would likely not have chosen to secede from the US Military and go rogue. Also, FEV changed the way the US Military interacted with its R&D elements, because the nature of the virus caused a whole lot of paranoia in the final days before the war.

Brotherhood of Steel would probably still exist, maybe in different locations and different leaders, with changed details. The actual idea is pretty broad.

Well, we might have seen something akin to the Desert Rangers taking their place; just US military survivors rather than the elaborate backstory of the Brotherhood.