I don't understand your reply. Two sources show that the US is 51st[1] and 40th[2] in the country rankings for life expectancy? I'm not sure what Japan and Korea have to do with it. Definitely not leading the field

[1] http://en.wikipedia.org/wiki/List_of_countries_by_life_expec...

[2] https://www.cia.gov/library/publications/the-world-factbook/...