Ukraine's spreading protests are clearly tied to a modern dilemma: Should the country's allegiance lie with President Vladimir Putin's Moscow, or with the European Union? Yet a look back into its history and geography helps explain why that question is hardly new, and how the passions and upheaval of today stem from centuries of battles over Ukraine's precarious position between East and West.

It was a history that created fault lines. Eastern Ukraine fell under Russian imperial rule by the late 17th century, much earlier than western Ukraine. This helps to explain why, after the fall of the Soviet Union, people in the east have generally supported more Russian-leaning politicians. Western Ukraine spent centuries under the shifting control of European powers