US State Department is the foreign affairs department of the US governemnt that promotes American foreign policy overseas. The propaganda unit of the American government, the US Information Agency (USIA), was folded into the State Department's Education Bureau in 2000. For more detailed information see former USIA employees Dr. Nancy Snow's book, Propaganda Inc.
On the State Department's own website, it states how they desire to use third parties to promote the government's agenda (put in link). Such third parties are universities, individual professors, TESOL organizations, churches, corporations, etc...
Out of the State Department are dispatched Regional English Language Officers who manage English language education in regions such as South East Asia, East Asia and South America. Under these managers, are English Language Specialists. One must be an American citizen to be an English Language Specialists. They are usually applied linguistics professors who go overseas as agents to find academics who are friendly to American foreign policy, aside from promoting English teaching.
Some English Language Specialists include Neil Anderson (Brigham Young University), Brown, etc... (give link)
These agents used to work under the propaganda arm of the US government, the US Information Agency.
The close relationship between American academics and the US State Department raise concerns about academic credibility. That is, research conducted by agents may be more interested in intelligence gathering for the government than for the goal of adding to a body of knowledge of linguistics.
The State Department also administers some language teaching programs for the US Department of Defense's Defense Language Institute.
The State Department publishes the English Teaching Forum magazine and distributes it to its embassies and military bases around the world.