Vladimir Putin has often cut a solitary figure as Russia's full-scale invasion of Ukraine drags on, but his position is bolstered by a deeply loyal entourage that has hardly changed in years. As commander in chief, ultimate responsibility for the invasion rests with him, but he is reliant on an inner circle, many of whom began their careers in Russia's security services. Wagner chief Yevgeny Prigozhin was once a close and powerful ally, but never part of that circle. So who does have the president's ear at this defining moment of the war? For months, two men have been in...