0_caf5b_53f2d8e0_XXL copyThe buildup of Russian troops along the Ukrainian border is large and getting larger, and it is raising serious concerns that Russia could invade Ukraine proper. Right now, there are as many as 20,000 Russian troops, complete with tanks and artillery, positioned just to the east of Ukraine. But other units deeper inside Russia appear to be on the move and could soon double the number of troops at the border. On Thursday, Defense Secretary Chuck Hagel called Moscow to ask Russia’s defense minister directly about the troop movements. MORE