I have two characters that I'm writing about, and I'm trying to write the conflict in a way that makes sense. They are both aliens - one male, the other female - from separate alien races, who are friends yet secretly have feelings for each other with neither knowing about the other's. The conflict is that the female alien is a doctor and hates violence (she is partially inspired by Mercy from Overwatch) because she grew up during a war that led to experiences in her childhood including seeing horrible deaths, losing her home and her left arm (thank God she's wealthy and future cybernetics technology). She finds out that her friend is a solider in the army - he's an engineer in his civilian job, but is also a combat engineer who has seen action and killed people in the line of duty. He enjoys being the army somewhat because he was a sickly child who had to work hard to overcome being physically frail - which he did ala Teddy Roosevelt (look him up) - and being in the army is this, a way of helping people and he's got something he's good at (she doesn't know those reasons). He's also not a solider in the army that subjugated her people - he's actually a solider in the army that liberated them - but her abhorrence of violence, seeing him kill someone (admittedly who was trying to hurt innocent people), his past and their feelings for each other make this a touchy issue. How would this kind of conflict play out in an engaging or realistic way and what would be a good way to resolve it? (my idea for the resolution is that she visits a war memorial, sees the sacrifices he and others like him face and learns about his past).