From a NY Times editorial of the same title (link):

The United States once had the world's top high-school graduation rate. It has now fallen to 13th place behind countries like South Korea, the Czech Republic and Slovenia. Worse still, a new study from the Education Trust, a nonpartisan foundation, finds that this is the only country in the industrial world where young people are less likely than their parents to graduate high school.

h/t: The Week