In a blaze of French style blending history and artistic audacity, the Paris Olympic Games opened beneath plumes of blue, white and red smoke, as thousands of athletes defied a downpour to sail through the city’s heart, down the Seine toward the Eiffel Tower.

Steady rain and rising security concerns could not deter the athletes from more than 200 delegations. They laughed, they danced and they waved national flags, some from the decks of converted sightseeing boats, in a ceremony dedicated to the theme of togetherness to heal a divided France and a fractured world.

Lady Gaga, emerging from behind pink puffballs in a black bustier, performed in French. Cabaret artists can-canned on the riverbanks. Aya Nakamura, a French-Malian singer whose presence was contested by the nationalist right, emerged from the august Académie Française, bastion of the French language, to offer her slang-spiced lyrics as she gyrated and stroked herself to the music of an impassive Republican Guard marching band.

A new and diverse France confronted an old and traditional France. At a moment of sharp political confrontation that has left the country deadlocked, the ceremony was an invitation to think again about the meaning of the nation and the possibility of understanding. The Republican Guard relented at the last and tried some modest dance moves in their military uniforms to Ms. Nakamura’s massive hit “Djadja.”