On December 8 , 2013 , the '' London Review of Books '' published " Whose Sarin ? " , an article rejected by the '' New Yorker '' and '' Washington Post '' in which Hersh argued that President Obama had " omitted important intelligence , and in others he presented assumptions as facts " in his assertion during his televised speech of September 10 that the Syrian government had been responsible for the use of sarin gas in the Ghouta chemical attack of August 21 , 2013 against a rebel-held district of Damascus . In particular , Hersh wrote of anonymous intelligence sources telling him that the Syrian army was not the only agency with access to sarin , referring to the Al-Nusra Front Jihadist group , and that , during the period before the Ghouta attack , secretly implanted sensors at the country 's known bases had not detected suspicious movements suggesting a forthcoming chemical attack in the period . The White House denied Hersh 's allegations , and a number of Syria and chemical weapons experts were critical of the article
Ghouta chemical attack
Ghouta chemical attack
Seymour Hersh