During a visit to Russia in July 2009, early in his presidency, Barack Obama spoke of his hopes for a "reset" in U.S.-Russian relations. "It must be a sustained effort among the American and Russian people to identify mutual interests, and expand dialogue and cooperation that can pave the way to progress," he said. To accomplish the "reset," of course, would mean one-on-one engagement with Vladimir Putin, then prime minister, now president, but always generally understood as Russia's most important decision-maker. Unfortunately, since the optimism of those early days, the path has been more than a little bumpy for Moscow and Washington thanks to obstacles such as an adoption ban, the Syrian civil war, and the fate of Edward Snowden. With today's news that Obama is considering canceling a meeting with Putin scheduled for September, here's a look back at the not-so-cordial encounters between the two leaders.