It‘s interesting, I feel this sort of character has largely fallen out of style. Very intelligent, intensely stubborn with an almost entirely immovable moral backbone, works for the military or a secret service but somehow still distrustful of authority and strongly individualist, largely does not show emotion but when they do, it is intense anger.
I can’t think of many examples, and a lot of them are more „still in publication“ rather than new, and their more recent appearances are much less like that. Best I can do is Jean-Luc Picard, Steve Rogers, Perry Rhodan.