RALEIGH, N.C.— As tensions grow along the border between Russia and Ukraine, a Duke University expert offers insight into how the conflict developed at the end of the Cold War. What You Need To Know Tensions between Russia and Ukraine began nearly 30 years ago, when Ukraine gained independence from the Soviet Union after the Cold War In response, the U.S. has sent additional troops to Europe, including 2,000 soldiers from Fort Bragg, North Carolina, to support its allies amid fears of a Russian invasion in Ukraine.