Vladimir Putin
The Obama Administration's hopes that Vladimir Putin could be ignored while cultivating President Dimitry Medvedev as the lynchpin of a U.S.-Russian "reset" were dashed in 2011. Putin thanked Medvedev for keeping his seat warm — aving been constitutionally barred from a third consecutive term as president — but having served as Prime Minister and power behind the throne since 2008, he now plans to run for president again next year. Medvedev graciously conceded that Putin would, indeed, be his party's nominee. But while the once and future president appears to be flexing for a more bellicose relationship with the United States, he hit a major speed bump in December as his party suffered a major setback in a parliamentary vote, despite claims of widespread ballot rigging in its favor. The accusations of fraud drew tens of thousands of protesters onto Moscow's streets in an unprecedented challenge to Putin, suggesting that his planned comeback won't be smooth sailing.