>>64386732
Personally the Narn were acting out in the start of the show, in a way you could consider some sort of cultural side-effect of the previous Centauri occupation. It is understandable, but their behavior was nothing more than a victim getting a taste of power and using it to bully anyone under them. Their continued behavior, even without the Shadow influence to the Centauri, would have provoked war sooner or later. However, the mass driver bombardment of the Narn homeworld is where the Centauri lose any real sympathy or at least claims of self defense, albeit that is the final blow of the war anyways.
And had G'Kar not found a new understanding to life alongside Emperor Vir, it would have continued back and forth like that over the centuries without any change. In a subtle way, I think that G'Kar wanting revenge but not actually knowing what else he'd do is a bit of foreshadowing that these feelings are more based on the suffering he endured and it's more of a reflex, just to try and fix whatever is wrong inside of his head. If they can do the same to the Centauri, then somehow 2 wrongs will make a right and he will be at peace. But also I don't think it's fair to blame Londo for not knowing the guy who looks like a stunt double for Alec Baldwin circa Hunt for the Red October who asks you a question is going to cause 'Make Hiroshima look like the Berlin Airlift,' from reminiscing wistfully.