troops this week with thousands more added to the estimated 100,000 already there. troops, military vehicles, and helicopters have flooded into this air base in belarus, and it is believed to be the biggest russian deployment there since the cold war. ukraine is now facing a potential invasion from three suds. you look at the map there. today the u.s. pulled 160 national guard troops who had been training in ukraine. and the state department offered -- ordered nonemergency u.s. employees at the embassy in kyiv to evacuate. it cited, quote, potential or significant military action. also today, thousands of ukrainians marched through the streets of their capital. the patriotic display in the face of the russian threat was called a march of unity for ukraine. well from the nation's capital to russia's cnn correspondents, we are tracking all of the latest developments