To better understand what's happening in eastern Ukraine, it helps to know what the region was like before the current crisis.
Daniel Drezner does know that. He lived in Donetsk back in the 1990s.
"Imagine the worst aspects of Detroit and Pittsburgh," he says. "It's a coal and steel mining town." Drezner is now a professor of international politics at Tufts University's Fletcher School of International Law and Diplomacy.
He says Donetsk is a place where everyone spoke Russian. He thought it had a Soviet feel to it. And even though it was Ukraine, an independent country, the people identified as ex-Soviet citizens.
Drezner says plenty has changed in the 20 years since he left. But he never thought Donetsk would be a flashpoint for a conflict between Russia and Ukraine. The armed intervention and stories of pro-Russian separatists taking over government buildings surprise him.
Listen to the full interview