Because they way they've written their relationship after CWII has left a lot to be desired

YES! They took what was an awesome friendship and just destroyed it. I don't understand why the conflict always has to be hero vs hero; it turns long-standing friendships into fodder for drama. That's a lot to throw away for very little gain.

Yes. Arno needs to disappear with everyone saying, "I don't remember any of that; what are you talking about? There's no Arno Stark."