"On Friday, the United States government apologized for experiments conducted in Guatemala in the 1940s, reminiscent of the Tuskegee study beginning in the 1930s, in which hundreds of African American men with late-stage syphilis were observed, but not treated for the disease." ("Tuskegee experiment déjà vu: U.S. apologizes for Guatemalan STD study;" Cindy Adams; Examiner.com; October 2nd, 2010; http://www.examiner.com/us-headlines-in-national/tuskegee-experiment-d-j-vu-u-s-apologizes-for-guatemalan-std-study)
A few days ago the above article would have been considered just another "conspiracy theory" and people would have rolled their eyes, because, "our government would never do such a thing!"
The history of U.S. covert chemical and biological warfare experimintation has been long and sordid. In 1995, the Clinton Administration appologized for decades of covert radiation experimentation on unwitting subjects. http://www.hss.energy.gov/HealthSafety/ohre/roadmap/index.html
In Israel an award winning documentary The Ringworm Children, documented how U.S. scientists with complicity of the Israeli government conducted radiation experiments during the 1950s on Sephardic children to test the effects of nuclear radiation. http://www.prisonplanet.com/articles/october2005/281005ringwormchildren.htm
Many of the children used in the "ringworm" experiments were Sephardic children from Yemen, who went "missing" following a joint CIA, MI6, Mossad operation code named "Magic Carpet," allegedly to rescue these children from Yemen. Interestingly, former director of Homeland Security, Michael Chertoff's mother, Livia, participated in this operation while working as a hostess for El Al Airline. http://www.rumormillnews.com/cgi-bin/archive.cgi?noframes;read=66175
Prior to becoming the head of Homeland Security, Michael Chertoff worked as a private attorney representing a New Jersey doctor, Magdy el Amir,who just happened to also be a financier of Osama bin Laden. But then you wouldn't know this unless you were into conspiracy theories. http://www.historycommons.org/entity.jsp?entity=michael_chertoff
Maybe sixty years from now the government will admit the truth about 9/11.