Boris Nemtsov was shot dead on a bridge just opposite the Kremlin 5 years ago. The murder, deemed political, was never solved. Why was Nemtsov killed? Was he lobbying too hard for sanctions against Russian authorities in Washington, wonders research journalist Andrei Soldatov.

Two weeks ago in Berlin a Chechen enemy of the Kremlin was murdered by, presumably, a contract killer dispatched from Moscow. According to security expert Mark Galeotti, Russian policy making is often 'driven by powerful intangibles such as honour, vengeance and reputation'.