China has closed its consulate general in Houston as ordered by the United States, the U.S. State Department said Friday after labeling the mission "a hub of spying and intellectual property theft," signaling that tensions between the world's two major powers have risen to their highest level in decades.In retaliation, the Chinese government has compelled the United States to shut its equivalent liaison office in the southwestern city of Chengdu in a development that could hurt their future diplomatic relations.Related coverage:READ FULL ARTICLE