International Relations (Security, Trade and Investment), 国际关系（安全，贸易和投资）

U.S. defence chief warns China, drawing parallel with Crimea
Agence France-Presse, April 6, 2014
http://news.yahoo.com/us-defence-chief-warns-china-over-territorial-claims-051903183.html

U.S. defense chief, in first, visits China's aircraft carrier
Reuters, April 7, 2014
http://www.reuters.com/article/2014/04/07/us-usa-china-hagel-idUSBREA350PR20140407