I thought this NYT piece was interesting (it's quoted in
@Ooh-Rah's post), credible, and terrifying (though exactly what anyone who watches the President would expect):
Forceful Chief of Staff Grates on Trump, and the Feeling Is Mutual
It seems to me an interesting - but not rewarding - ethical case senior military officers have made for themselves in the administration. They have lent President Trump their credibility and competence - bolstering his credibility across the board and giving him some rare functional enclaves inside the executive. However, the President's character has proven to be almost impossible to influence - so these men's influence is almost totally limited to decreasing the damage the President does versus actually progressing policies.
EDIT: Also meant to mention I still wonder at their argument about 'duty' to serve. I definitely get we don't choose our boss in the military and it's a huge part of our job to help make them successful regardless of our feelings about them. But, that's in a military or national security context - where the policies, procedures, duties, and responsibilities they are executing are in line with organizational objectives. In a political context the President is deciding all those things himself. No one would argue you need to support a boss in the military who is doing unethical or immoral things - and there's a strong argument to say you should oppose them when they're doing stupid things. So, I think it's very difficult for these senior military leaders to argue at some point - as I know at least GEN Mattis has done - that they are just 'serving the best they can as is their duty.' It is more accurate to say, IMO, they have chosen to support the policies, views, and ultimately character of the President. I think more and more evidence is stacking up that's going to lead them to actively support a bunch of stuff they might not like being associated with. Also, if you are making the argument you're serving out of a sense of duty and not 'deciding' policies themselves - thus limiting your agency and culpability - I think articles like this show they're doing a bad job. If you're really going to serve as a subordinate - in a military sense - I think the onus is on you to execute your bosses intent, as long as it is moral, legal, and ethical - and resign if you cannot. I don't think a part of that ethic is to slow-roll, undercut, or fail to comply. I mentioned before it makes me very uncomfortable to see senior military leaders not acknowledge and execute Presidential guidance - even when it's fucked up, stupid, and poorly done. Civilian control of the military is a core tenet of the republic. It seems to me these senior military leaders want to have it both ways - they want to be able to manipulate in order to influence but they don't want to face any of the consequences for poor behavior because 'they're just doing their duty.' I don't think that's an argument that's going to hold up over time.
I think history - even without a long reflection time - is going to be very unkind to these senior military leaders and I wonder at the impact on the flag officer ranks after this administration. I think GEN Kelly could have had a sympathetic biographer if he had just been the DHS head during the administration - but now that is impossible. Each of these senior military leaders have fashioned themselves into active enabler of the President - tying themselves intimately to his personal and professional flaws. Currently they're all getting a lot of credit for being the 'sane' and 'reasonable' members of the cabinet. But, as those immediate crises pass that goodwill is going to evaporate IMO.
I think LTG McMaster's 'Dereliction of Duty' treatise that got him so much praise as a more junior officer is going to end up as a massive monument to irony.