The first code of ethics by the American Anthropological Association, adopted in 1971, was forged during the Vietnam War, years after revelations that anthropologists had engaged in counterinsurgency research in Southeast Asia. Now, in response to issues raised by the war in Iraq, the author advocates that it is time for a new code. Members of the Commission on Engagement of Anthropology with the U.S. Security Community, convened in 2006, have been grappling with framing ethical standards for anthropological work undertaken in connection with military, defense, and intelligence agencies. Two of the key issues are secret research and the Commission injunction to do no harm. Avoiding secrecy and harm when pursuing national-security research may sound simple. But the author contends that sometimes it is not, as anthropologists are discovering in trying to rework their code of ethics.