Observers say Putin is under pressure at home and abroad . U.S. officials : Ukrainian troops moving closer to Russian border . Malaysia Airlines spokesman says missiles may have been fired from U.S. . The shootdown comes six days after Ukrainian security council Flight 17 was brought down .
Observers say Putin is under pressure at home and abroad . U.S. officials : Russian troops moving closer to Ukrainian border . Ukrainian security council spokesman says missiles may have been fired from Russia . The shootdown comes six days after Malaysia Airlines Flight 17 was brought down .