The Obama administration found itself in the cross hairs of mounting Republican frustration Tuesday over national security policy, with particular focus on unanswered questions surrounding the Boston Marathon bombings last month and the terrorist attack last year on the U.S. Consulate in Benghazi, Libya.

The Obama administration found itself in the cross hairs of mounting Republican frustration Tuesday over national security policy, with particular focus on unanswered questions surrounding the Boston Marathon bombings last month and the terrorist attack last year on the U.S. Consulate in Benghazi, Libya.

The State Department sought Tuesday to discredit a media report that claimed the Obama administration has threatened CIA and State Department officials in an attempt to intimidate them from cooperating with lawmakers seeking information about the September 2012 attack on a U.S. diplomatic post in Benghazi, Libya.

The White House said Thursday that military forces loyal to Syrian President Bashar Assad probably used chemical weapons on a "small scale," reigniting the debate over what role the U.S. should play in trying to topple the regime.

Maine Sen. Angus King says the FBI is getting a bad rap on its investigation off the Boston bombings, saying it doesn't appear the agency mishandled an earlier inquiry of suspect Tamerlan Tsarnaev after Russian officials warned he could be dangerous.

Federal investigators told Capitol Hill lawmakers Tuesday that the Boston Marathon bombing suspects appeared to work independently — getting their ideology and bomb-making skills online — and that the case revealed intelligence-sharing shortcomings.

The FBI did not know that Tamerlan Tsarnaev, the older Boston Marathon bombing suspect who was killed in a firefight last week, took a six-month trip to Russia because his name was misspelled, according to Sen. Lindsey Graham.

U.S. and Libyan authorities investigating the Sept. 11 attack on the U.S. diplomatic outpost in Benghazi are being hamstrung by the Libyan government's lack of control over the eastern part of the country.