It is up to the beholder. http://en.wikipedia.org/wiki/Western_world Your list should not include Israel but should include Siberia/Russia if you went by the grouping given on wikipedia. It depends. Geography, religion, standard of living, etc. Plenty of ways to group them. If maps were drawn differently or if the other sides had won in world conflicts throughout time, the entire definition in the minds of everyone would change.
Considering the number of Murikan registered professional fighters coupled with the Murikacentric boxing infrastructure and it is amazing they do not have 5x the number of top fighters and have top dogs in every division above FW.