As the crisis in Syria collapses into what looks like full-blown civil war, Russia's response stems from a complicated mix of principle, self-interest, mistrust of Western motives, and differing perceptions of the situation.
The agreement, which could see Russia build eight new civilian reactors in Iran, comes just weeks before a deadline for Iran to accept curbs on its capacity to make nuclear weapons.
While Russia's plan for securing Syrian chemical weapons gains traction, experts warn of serious challenges.
Allegations of voter fraud in Russia are nothing new. But this time it's the Kremlin making them.
Secretary of State John Kerry sought to ease diplomatic tensions with Russia in preparation for meetings between Putin and Obama later this year. But Syria remains a major sticking point.
Russia warned the US about the future Boston Marathon bomber back in 2011. But when Mr. Tsarnaev returned to Russia the next year, authorities there apparently left him alone.
The country faces two competing visions of democracy, one that emphasizes majority rule versus another that stresses minority protections.
Moscow is criticized for weak support of the Arab Spring, and for actively backing Bashir al-Assad in Syria. But the Kremlin says its policies are consistent and the West is exporting revolt.
The new law, enacted in the US last week to target Russians involved in the death of lawyer Sergei Magnitsky, has infuriated the Kremlin, which sees it as a 'purely political, unfriendly act.'
Many in Moscow see Putin's invitation to Obama to visit Russia as diplomatic decorum unlikely to warm a chilly relationship. But others suggest that the Russian leader may be ready to deal.
Vladimir Putin, once again in the Kremlin's top post, faces a far more divided Russia than he did during his first stint, and he's taking a more authoritarian line to match.