After 10 months of intense combat, the war in Ukraine heads into a cold and dark New Year. For Ukraine and its president, Volodymyr Zelenskyy, it is a fight for survival; for Russia and its president, Vladimir Putin, it’s a military debacle. CBS News national security correspondent David Martin talks with military scholar Fred Kagan about the prospects of Russia breaking the Ukrainians’ will to fight as Putin attacks their cities and energy grid.