FILE - This May 22, 2010 file photo shows President Barack Obama speaking during commencement ceremonies in West Point, N.Y. The president will use his commencement address at West Point Wednesday to defend his foreign policy against criticism that he has relinquished America's global leadership and stands by idly as problems erupt in the Middle East, Russia, China and beyond. (AP Photo/J. Scott Applewhite, File)
France's Kristina Mladenovic reacts as she defeats China's Li Na during the first round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Tuesday, May 27, 2014. (AP Photo/David Vincent)
Sloane Stephens, of the U.S, returns the ball to China's Peng Shuai during the first round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Tuesday, May 27, 2014. (AP Photo/Darko Vojinovic)
Sloane Stephens, of the U.S, returns the ball to China's Peng Shuai during the first round match of the French Open tennis tournament at the Roland Garros stadium, in Paris, France, Tuesday, May 27, 2014. (AP Photo/Darko Vojinovic)