I think many people rely on mixed messages & impressions of the US armed forces from TV shows like Gomer Pyle USMC
or Hogans Heroes
It's been nearly 2 decades since I was in the US armed forces & Im sure
that rules/SOPs/ROEs/etc have changed a lot.
Today's forces must be very aware of the laws/memoranda/orders. Lawyers & legal advisors are a part of every
op or mission.
There's no "aw shucks" or "hey so what" mindsets anymore. If you shoot anyone, even in combat, it better be explained or justified.
I even heard pilots & air crews used caution with bombs/ordinance in OEF/OIF because they didn't want to cause "collateral damage" or "accidents".