Apparently they do not have such an obligation - after all, CSTO refused to help Armenia in the recent Azerbaijan-Armenia war, so from that perspective it's a b

Apparently they do not have such an obligation - after all, CSTO refused to help Armenia in the recent Azerbaijan-Armenia war, so from that perspective it's a bit surprising now CSTO including Armenia itself seems to consider that it's an obligation given that this case is obviously much less applicable than that war.