Why would Putin invade Ukraine again?
Nearly eight years after Russia invaded and took control of Ukraine's Crimean Peninsula, 100,000 Russian troops have recently built up along the border of Ukraine. CBS News national security correspondent David Martin talks with former NATO ambassador Ivo Daalder and retired Lt. Gen. Ben Hodges about what President Vladimir Putin hopes to gain with a possible invasion, and what the consequences may be – for the Kremlin, and for Europe.