CANNES, France — President Obama plunged Thursday into the fast-moving European debt crisis, arriving here to exhort European leaders to get their financial house in order.

But while the president hustled from meeting to meeting with world leaders, he was in many ways thrust into the rare position of bystander, as the unfolding drama over whether the Greek government would fall (it did not) and whether Greece would back the comprehensive accord to protect the euro reached last week (it will, at least for now) dominated conversations in the hallways and conference rooms here in this iconic seaside town.

The grand Espace Riviera is more accustomed to red-carpet arrivals by movie stars and hangers-on for the Cannes Film Festival; on Thursday it was transformed instead into ground zero for blue-suited bureaucrats grappling with a financial crisis and the global contagion that it threatened.

Instead of Angelina Jolie posing before the paparazzi, it was Chancellor Angela Merkel of Germany holding a frozen smile as she greeted Mr. Obama in front of the cameras. There was little preening before the hundreds of reporters gathered from all over the world; President Nicolas Sarkozy of France quickly swept Mr. Obama into a meeting to discuss how to try to stop the unfolding Greek drama from turning into a tragedy, for global markets at least.