From the CIA’s 2011 style guide, recently acquired by the National Security Counselors, a legal nonprofit, following a Freedom of Information Act request.

decimate : Originally meant to select by lot, and then to kill, one out of every 10 in a group of enemies. Now it is used (and overused) to encompass heavy losses of many kinds. Use it only when referring to people, and only when actual deaths are involved.

disinformation, misinformation : Disinformation refers to the deliberate planting of false reports. Misinformation equates in meaning but does not carry the same devious connotation.

may, might : Both may and might deal with possibility. Might carries an implication of greater uncertainty on the part of the writer. Country A may invade Country B if President X gets the support of Country C. Country A might invade Country B if President X can persuade the legislature to back him.

impact : Verbs such as affect or hit are preferable to impact. If you do use it as a verb, you should always use it intransitively. A missile does not “impact a target”; it impacts on a target or in a target area.

Russian submarines : See section 7.6e for information on Russian submarine designators and footnote 39 for a list of submarine names.

torturous, tortuous : Torturous means extremely painful. Tortuous means twisting, devious, or highly complex.

while : As a conjunction, usually has reference to time. While the President was out of the country, the Army staged a coup. It can, with discretion, also be used in the sense of “although” or “but.” While he hated force, he recognized the need for order.

regime : Has a disparaging connotation and should not be used when referring to democratically elected governments or, generally, to governments friendly to the United States.

Free World : Is at best an imprecise designation.