Adm. James Winnefeld on N. Korea: "Let them stew in their own juice"
Retired Navy Adm. James "Sandy" Winnefeld was vice chairman of the Joint Chiefs of Staff for four years under the Obama administration and was previously tasked with preventing air attacks against North America as commander of NORAD. Winnefeld joins "CBS This Morning" from Washington to discuss why he believes North Korea is using the nuclear threat as a "survival mechanism," the strength of the U.S. missile defense system, and why his biggest national security concern is Russia.