U.S. Defense Secretary Chuck Hagel, left, meets with Chinese President Xi Jinping at the Great Hall of the People Wednesday, April 9, 2014 in Beijing, China. (AP Photo/Alex Wong, Pool)
Defense Secretary Chuck Hagel announced that he authorized releasing details of the U.S. cyber warfare doctrine to China in a bid to win cooperation from Beijing. (Associated Press)
Defense Secretary Chuck Hagel shakes hands with Chinese Minister of Defense Chang Wanquan prior to their meeting at the Chinese Defense Ministry headquarters in Beijing, Tuesday, April 8, 2014. (AP Photo/Alex Wong, Pool)