Valerie Gerasimov is a rather grey 67-year-old general who has reached the top position in Russia's army. The Kremlin linked the move to a need to tidy up the command structure, but look a little closer and it seems to send a message about who holds the power. He oversaw Russia's seizure of Crimea in 2014, as well as its brutal campaign in Syria in 2015. But now he will be even more visible as he is to become responsible for everything that goes right and wrong in Russia's invasion of Ukraine.