Football icon Andriy Shevchenko, one of the most recognizable Ukrainians on the world stage, has called on his homeland to stand together in the face of the threat from Russia. Russia has recognized two separatist regions in eastern Ukraine as independent countries and has authorized military forces to enter. “Today is a difficult time for all of us. But we have to unite,” the former Ukraine and AC Milan striker, who lives in London, wrote on Instagram and Twitter on Wednesday. “I have always been proud of my people and my country. We have gone through many difficult times and in the last 30 y…