However, that depends on the people between the president and nuclear launch being decent human beings that care about law and order and proper procedure. You need to look at the system, not just individuals.
Alternatively, let's say someone came to power who genuinely believed nuking Russia was a good option. Rather than order a launch on the spot, what they'd actually do is gradually build a case, appoint pliable or similarly thinking people to key positions, get the launch protocols revised, engineer a geopolitical crisis by provoking Russia and drive events towards a situation in which a nuclear launch seems like a legitimate option.
http://blog.nuclearsecrecy.com/2016/11/18/the-president-and-...
You might say "sure, but there are people who have to actually execute those orders." But give the Pentagon some credit--those are people who have been systematically selected because they follow orders quickly and without question. For example, consider what happened to Harold Hering when it became obvious that he was not one of those people.
Which is why President Obama pivoted to a drone war in areas like Pakistan. Scores of Pakistani civilians are killed on a regular basis for crimes no worse than standing next to a tall bearded man or attending the funeral of a neighbour. The American public has no issues with this because hey, it's cheap to deploy the drones and no American lives are ever in jeopardy. And to be fair about it, apart from the high collateral damage, the Drone War in Pakistan is generally considered to be successful at inhibiting the Pakistani Taliban.
This Drone War was the first successful war that we've seen fought without boots on the ground. It's likely that we'll see many more like this as on-board AI improves.
In Nuremberg we developed a way to think about this: people outside the central circles of power have a tremendous amount of pressures they are considering. It's definitely the case that some are sadistic and horrible, but more are just following orders and trying to get by as best they can, and punishing them for war crimes is not appropriate.
The other side of that coin is that it isn't realistic to expect soldiery en masse to resist illegal orders. It's always more complicated than that.
And then there's always that soldier ready to denounce his camarads for having raped some poor Vietnamese women who had nothing to do with the war itself. Why risk such a PR disaster which might see your funding cut when you can use robots instead? Warzone robots don't snitch on their fellow robots in front of the press and they don't rape, they're only build to kill.
Actually, the unwillingness of the Red Army to do any more invasions was arguably the precipitating factor in the fall of the Soviet empire. In 1988, Gorbachev gave a speech to the Warsaw pact meeting where he told them that the Brezhnev doctrine was no more. No socialist government would be able any longer to count on Russian aid in putting down popular uprisings. A year later, the empire crumbled. Of course, it wasn't the soldiers per se who refused, but the generals who were afraid of the potential mutinies (and the occasional actual ones).
And economic problems were a big incentive for everyone in charge to step back from wars. For country's with a strong economy there would be little incentive to stop, especially if AI makes war cheaper.
https://en.wikipedia.org/wiki/Nuremberg_Principles#Principle...
What horrible things to you have in mind that armies have not already done?
We speak of Nazis frequnetly, but consider what Curtis LeMay did in war and prepared to do after the war.
AI and robots give plausible deniability and reduce the number of witnesses. They also make suicide raids more practical.
Or American death squads in Afghanistan. Might as well call them rape and death squads.
What about Guantanamo?
Srebrenica?
Should I go on?
How unenlightened and naive are you?
Currently there's a high cost to it. War is very expensive; even the richest country in the history of the world, the US, doesn't want to bear the costs. And it requires persuading masses of soldiers to go along with it.
Roboticized warfare might eliminate those constraints.