The police in the U.S. seem to think like they are in the military , in their training and tactics. One big problem is the U.S. military is not exactly well regarded for is nuanced handling of conflict.
I once spoke to a marine who was involved in the invasion of Bagdad who describe their rules of engagement as "shoot any man woman or child holding a spade, a mobile phone, any kind of parcel or anything that might be a wire". These ROE are almost certainly a war crime, but the US is special so it gets away with it.
Now in the military you have a bunch of guys who actually have to deal with very dangerous, fluid situations that have a high likelihood of death. They mostly operate in areas where you have little room for anything other than binary control (obey or get shot). Whatever the details of the culture that was set down by the high ups before the Iraq invasion, I can somewhat get onboard. Casualties in a war zone are logistically hard, getting effective treatment often means at least some part of running them on a stretcher, potentially strapping them to the back of a vehicle and driving for an hour. If you aren't conservative in how you instruct people to respond, the effect can be highly non linear. One casualty take a 3 others out the fight, meaning casualties become more likely etc.
How police respond simply should not be modelled on the military. I entirely disagree with the idea that they are constantly primed to consider themselves one stop away from a body bag.
They almost certainly interact with more innocent members of the public than criminals. They are in largely stable situations. They may deal with bad people, but they do so in places that have good access to support, they will get timely care if something happens to them, and they almost certainly are well backed up if the situation gets out of hand.
My opinion is that the police basically suffer from a kind of dunning Kruger effect. Most would be woefully unprepared to handle an actual combat situation. You just have to compare the countless videos of about a dozen cops all unloading at the same car like the first to finish gets a prize.
Being a good solider is about maintaining discipline and composure under pressure. Most unit tactics involve some variant of your unit shooting over your head or off to your side whilst some of you push some kind of flanking manoeuvre. Our military even dropped the shoot from the hip on contact SOP because of the risk of friendly fire.
The police do not have anywhere near the same level of conditioning to operating under pressure from their training as any competent army gives it's soldiers. If they want to act like the military that's fine, but they should go through similar training before they do.
Yes. What is and what is not a war crime is determined by the ICC in the Hague. The US does not recognize the authority of the ICC.
Per definition, no US soldier can literally ever commit a war crime.
So in that respect, they are not a whole lot different from US police. They can commit atrocities and get away with it.
It's like as if Germany decided to just not show up at Nuremberg.