Mikhail Khodorkovsky was Russia's leading businessman and an outspoken Kremlin critic. Under his leadership, the oil company Yukos revived the Russian oil industry, and as the company thrived, he began sponsoring programs to encourage civil society and fight corruption. When he was arrested at gunpoint in 2003, Khodorkovsky became Russia's most famous political prisoner. Sentenced to ten years in a Siberian penal colony on fraud and tax evasion charges,...