Not since Josef Stalin has anyone ruled Russia for so long. On May 7, Russian President Vladimir Putin was inaugurated for his fourth term, ushering in another six years as leader of the global power. Putin lauded the country during his elaborate swearing-in ceremony at the Kremlin, praising it as a "strong, active and influential participant in world affairs." But despite his bold tone and familiarity with his post, uncertainty over the pressing challenges facing the country will dominate his latest -- and perhaps last -- term in office....