Saw George's thread that brought me to this one.
This article goes into the qualities that make a country safe. Of course wealth, education, justice system... I know Singapore comes to mind when I hear of safe countries. I've heard you could leave an Apple MacBook Pro out on a counter top in a coffee shop all day and it will not get stolen.
That being said, there are hard to define (and politically incorrect, I guess) reasons why some countries are safe, too. I'd say very generally there needs to be a collective culture that expects safety and has a unified set of values. It's hard to have that in poorer countries, or countries with external conflicts, or countries (like the US) that is a melting pot a mixed salad of cultures with some resistant to assimilation for a more homo cultural experience. Homogeneous, of course.
https://worldpopulationreview.com/country-rankings/safest-countries-in-the-world
