Mattis has been sharply critical of President Barack Obama's policies on Iran and Obama's capping of troop numbers and campaign end-dates in theaters of war such as Afghanistan and Iraq. Mattis also appears to be a skeptic of the Obama-era policy of putting women into combat roles.

Since Snowden went public, companies such as Apple and Google - two of the world's most valuable companies - have incorporated much greater encryption into their products and have also been at pains to show that they will not go along with U.S. government demands to access their encrypted products.

Investigations by special prosecutors can take on a life of their own.

Peter Bergen Quotes