[alkonaut]

There are obviously levels of this problem. On the worst level (I hope it's the worst) you have people consuming a completely different reality. I'd argue the US has arrived there. The test for having the problem at this level would be if you could ask a population a question with an objective easily known factual answer and have a significant fraction disagree with the answer because of their news diet.

The UK has the problem at a smaller scale. Other western countries have problems with trust in media but I'd argue they don't have the same level of invented reality as the US.