Movement in Moscow: Does economy minister's arrest signal wider Kremlin purge? (part 1)

Russia's economic development minister Alexei Ulyukayev has been arrested for extortion in the highest-level detention Moscow's seen since the 1991 failed coup. An anti-corruption crusade? Or was he collateral damage in the Kremlin rivalry between the military and intelligence brass and the suits working to keep Russia open for business in times of sanctions and low oil prices? And now that Donald Trump's elected, will it be win-win and a toning down of rivalries all around in Europe and Syria?