After the war, there were many summary executions of accused collaborators, reportedly numbering in the hundreds. In an attempt to restore order, de Gaulle and others created the "universal resistance" myth that essentially claimed that everyone was part of the resistance. It just wasn't true, but if it served to stop the executions, it was understandable (especially if the executions were starting to reach those in the political classes).

On page 7 of this document, you'll find the following:

“This is the France of yesterday,” said Weisberg. “Of course, the laws were removed from the books as each town and city was liberated. But the postwar period in France (1945–1946) needs our attention for a moment. What happened to the property that was taken away from the Jews? What happened to the property that was aryanized? What happened to law practices that were stripped away? Were there any reparations? Was there any judicial or other kind of trial of the individuals who were involved in this terrible process? The answer is either no or very little on all counts. What ensued in France is called the Vichy Syndrome. Americans must keep in mind that we have periods in our history where we would prefer to forget something, and where myths take over for realities.”

Under President de Gaulle, universal resistance was the myth that the French purported about Vichy. When Weisberg began his research in 1982, he couldn’t get into many archives, and nobody wanted to speak about this terrible era. “When I did interview people, they would say, ‘we were all in the resistance.’ I knew from the records of some of the people I was talking to that that just wasn’t true. Eventually, I would just stare at someone incredulously, and their eyelids would droop down, and they would say, ‘at least after 44.’ Which, of course, was after all of the harm had already been done.”

However, about this period de Gaulle has said, “France was elsewhere.” Notes Weisberg: “He says that because he was elsewhere; he was in Britain mustering up Free French forces. But there were 40 million French people left in France. From de Gaulle through Mitterrand, there was no change in that myth. However, Mitterrand, who was a leftist, deserves credit because he at least opened up the archives to people like me when no one had been allowed to look into them. But it wasn’t until Chirac, in the summer of 1995, that a president finally said, ‘France is responsible for what happened during Vichy; we were all there; we weren’t all part of the resistance.’ ”

Has the French myth been turned around because of Chirac’s statement? “Yes and no,” answered Weisberg. “More and more material is coming out about Vichy. Jewish historians courageously amassed documents during the period itself and have set up a wonderful documentary center in Paris. A handful of French historians are writing about the period. And there have been several notable trials, including a war crimes trial against a French bureaucrat whose behavior was very similar to that of the French lawyers I have been describing. Yet, if you watch what has been going on, the myth has great endurance. Each country in Europe had its own myth. The French myth is proving to be enormously important to them. So much so, that I don’t think it’s turned around.”

From the reviews, it seems this book may be a good reference on the subject.