Leon Panetta

The national security apparatus of the United States is a huge machine that incorporates a myriad of officials - from the commander-in-chief and members of his cabinet, to ambassadors and desk officers, to military and intelligence personnel.

Turkey and the U.S. should establish a base of action in a planned safe zone in Syria in order to ensure that "Syria goes in the right direction," former Pentagon and CIA chief Leon Panetta has told Hürriyet Daily News in a telephone interview. 

President Barack Obama has nominated former senior Pentagon official Ashton Carter as US Secretary of Defense.

If confirmed by the Senate, Carter will replace outgoing Defense Secretary Chuck Hagel, who resigned in November.

Administration sources said on Dec. 2 that U.S. President Barack Obama has settled on the 60-year-old Ashton Carter as his fourth defense secretary, with an announcement expected in coming days once he is thoroughly vetted.

Chuck Hagel is to resign as US Defense Secretary, according to reports of US media outlets.

Information from the New York Times suggests a shift in Washington's military strategy against the Sunni extremists from Islamic State (IS) will result in Hagel's decision to step down, which has been taken "under pressure".

Reportedly, he has already submitted his resignation.