Paris was the capital of France.
Sydney (under the alias Amanda Peterson) went to Paris with the intention of getting arrested so she could break into the French police's evidence archives and steal the Decoder key for the Blackwell Index. As part of the cover, she spray-painted and smashed up a car owned by Eric Weiss (posing as an irate Frenchman) to get herself arrested. Marcus Dixon then arrived as her council from the American Embassy, Richard Zachary. Dixon shot the guard with a tranquilizer and gave Sydney the CD burner to get the decoder key. She made it to the location of the decoder key, and managed to get it. However, French police found her. Sydney had to run to the roof and jump onto a chopper piloted by Weiss just before she was shot (The Index).
On a separate mission, Sydney, Vaughn and Dixon were in Paris. Sydney was in the field with Vaughn observing and Dixon running tactical. As Sydney got into position, Vaughn reported that there was no sign of Connelly. He soon arrived and they proceeded with their transaction; Connelly was selling a chip to Sydney for a large cash sum. He said that he hoped to get a house on the Mediterranean and maybe get a dog. Before he could continue, however, he was shot. Vaughn took down the man who shot him, but did not kill him. The man said that he would not be made an example of, then slit his throat (The Road Home).