BBC definately broadcasts international news, it is BBC World I think.
Re Ariel. My experience of news channels in the US is that they do show international news, certainly much more than is being shown on news channels here. Admittetly, not as much as the BBC or other world channels though, most international news in the US is because it directly impacts the US. I wonder if the lack of international coverage on Argentine news channels is because the country is not a big player, so to speak, on the international stage. Obviously UK and US (others too of course) channels shows more international news because those nations are more impacted by international events.