You already replied to it, here the text again:

I mean otherwise [from context: saying that financing terror groups is a thing peaceful countries do] you could make similar claims about the US. Such a peaceful country! It wasn’t them overthrowing the legitimately elected governments, but local resistance groups! Who trained and armed them? How does this relate to the conversation?

Here, what Iran does is applied to the US in an ironic manner, because I, the writer, assume that nobody thinks the US is a peaceful country, because I don’t think so either, hence calling them out though indirectly; but again nobody called them peaceful (rightfully so), so there was no need to spell it out, I assumed.