Washington Post: Two senators accused the Obama administration Thursday of impeding an investigation into whether the government missed warning signs leading up to the Nov. 5 shootings at Fort Hood, Tex., threatening to subpoena documents from the FBI and Pentagon if they are not delivered by Monday. Sens. Joseph I. Lieberman (I-Conn.) and Susan Collins (R-Maine), the chairman and ranking minority member of the Senate homeland security committee, said they requested, among other documents, the personnel file of the alleged shooter, Army Maj. Nidal M. Hasan, and his communications with Yemeni cleric and suspected terrorist Anwar al-Aulaqi.