[roenxi]

That isn't actually the tu quoque fallacy, although it does look quite similar at first glance.

A = [commit murders on foreign soil, invade other countries and other nasty things] B = [made this relationship a lot less attractive] C = [it is wise to improve our relationship]

The original claim is A -> B, A(Russia) -> True.

The response is that A -> B, A(US) -> True. Therefore, if C(US), C(Russia) is also not ruled out. Logically sound.

This isn't claiming that rbanffy's argument is wrong because A(rbanffy). I suspect rbanffy is probably not even committing murders on foregin soil, le alone the other stuff, so it isn't a tu quoque fallacy. It is just pointing out that A isn't an international norm for cutting off productive relationships.