Hall Gardner, political science professor at the American University in Paris, said the revelations “upset a balance between what is stated in public and what is stated in private".
"What this is going to do though is to make diplomats think twice, if they think that what they write or say is going to leak out, they will refrain from saying it. Therefore you won't get complete information and you won’t get that personal touch that the diplomats will normally engage in."
Earlier French government spokesperson Francois Baroin called the documents' release a "threat to democratic authority”.
"We stand united with the US administration on the desire to avoid that which not only damages states' authority, the quality of their services, but puts men and women who have worked in the service of the country in danger," he told Europe 1 radio.
The WikiLeaks disclosures include documents relating to a nuclear standoff with Pakistan and to Arab leaders urging a strike on Iran. They also tackle a Chinese government bid to hack into Google and plans to reunite the Korean peninsula after the North's eventual collapse.
The confidential cables, most of which date from 2007 to last February, also reveal how the State Department ordered diplomats to spy on foreign officials and even to obtain their credit card and frequent flier numbers.