You should care less about the murder rate by nation and more by city or neighborhood. Chicago and Detroit are thousands of miles away from where I live - what relevance is the murder rates in those cities to me? Someone living in Alaska would have to cover a quarter of the surface of the globe to reach Key West Florida...why would they feel impacted by the crime rate there?
Go look at a heat map of per-capita gun homicides in the US. This is not a "national" problem. Communicating this has been very challenging for people who live in Chicago in particular - everyone thinks the entire city is a killzone, when in fact there are perfectly safe neighborhoods, and other neighborhoods that are a warzone. But if you were to only see the citywide statistics for Chicago murders, you wouldn't even leave the airport.