It is unlikely, given the animosity that exists between the two countries, that too many Serbians would take heed of the uttering of an American president. But for Belgrade's favourite son, Novak Djokovic, Barrack Obama's "Yes We Can" slogan from the 2008 American Presidential Election should be adopted as he attempts to win his first French Open title.
If Djokovic truly believes, he will have a great chance of relieving Rafael Nadal of the French Open trophy, a bauble that looked set to be set for permanent residence in the Spaniard's trophy cabinet. The omens are good, the Serb, having ended the "King of Clay's" two-year unbeaten reign with titanic victories in Madrid and Rome.
The 24-year-old Serbian is in the form of his life, unbeaten on any surface in 37 games and the clear leader of the pack attempting to find room on the pantheon beside the two greats of 21st century tennis—Nadal and Roger Federer.
Two victories over Nadal on clay in the last month would suggest that Roland Garros will be acclaiming a new champion in a fortnight.
Yet the doubts linger. As my colleague, Satish Subbaraman writes in his excellent article, there is still the fear that Djokovic may fail to fulfil his potential, like the supremely talented Russian Murat Safin.
However, while Safin was a gifted player, to this observer, he was never able to control his wild temperament. I don't see that problem with Novak, who has appeared this season both physically and mentally stronger than at any time in his career.
While is it would be stretching things to suggest the Serb exhibits Lendlesque control over his emotions, he does have an inner steel that carried him through against Andy Murray in the Rome semifinal last week and his physical resilience meant he was able to defeat Nadal in the final the following day.
His route to the final is not an easy one either, with dangerous potential opponents Del Potro and Richard Gasquet waiting in the later rounds. A fourth round tie with France's best hope for glory , Gasquet, Federer's conqueror in the Italian Open, in front of a partisan crowd would be an interesting, if unwanted, test for the Djokovic confidence.
But it does appear that the Serb believes that he now belongs at the pinnacle of men's tennis; what was striking about his victory over Andy Murray in Australia in January was that at no time did Djokovic look as if he thought he would lose, whereas Murray seemed to be hoping he might win, Djokovic seemed to know he would.
Nadal on the clay in Paris may be a different proposition to Murray and it would be lunacy to consign Federer to history despite his poor form, but there is now a third man at the summit of the sport and he is not only a man that can, as far as the French Open is concerned I think he is a man that will.