Open Doors has just come out with the 2014 numbers for international students in the U.S. The breakdown by country shows that China continues to dominate, accounting for nearly a third of all foreign students. Saudi Arabia, which is now funding students' university study, sends nearly as many students to the U.S. as South Korea.
While international students only account for 4% of the U.S. total, they're more significant than their numbers would suggest since they often support programs such as engineering that would shrink or disappear at many schools without them. They're also a heavy presence in graduate programs. Nearly a third of these students are in California, New York, or Texas. The gap between Korea and Japan is odd. Japan has over double the population of South Korea (around 127 million vs. approximately 50 million), yet sends less than a third as many students abroad (to any country) to study. Looking at the numbers, we shouldn't conclude that the U.S. educational system has been doing well. In terms of the actual share of international students, the U.S. has been getting a significantly smaller portion over the last decade, losing out to European countries.