The period of ''cohabitation'' between the Socialist president and a conservative parliament, with Jacques Chirac the prime minister in 1986-88, left the conservatives discredited, as the Popular Front had been discredited a half-century earlier. The right had seemed to demonstrate an incapacity to subordinate partisan to national interest and to be incapable of uniting the nation.
Today, scandals gather around the Socialists' uses of power. They have become complacent in office. The party is divided by the struggle for Mr. Mitterrand's succession.
The public might well prefer an alternation of government in 1993, or before, if the conservative parties could overcome their divisions and end the paralyzing rivalry of Mr. Chirac with former President Valery Giscard d'Estaing.
Mr. Mitterrand nonetheless ends his decade in the presidential palace with the balance of left with right reversed. He has completed what DeGaulle began, reconciling the French to one another, demonstrating their essential consensus on the fundamentals of national purpose and policy and validating the constitution and political institutions that were DeGaulle's legacy.
There is a nice irony to it. The old enemies enter the history books as complements of one another. DeGaulle's accomplishment had to be completed by Mitterrand. $ 1/8 Mitterrand's accomplishment would have been impossible without DeGaulle.
Neither, no doubt, would have wanted it this way. Both, one would think, would be capable of appreciating the irony. The French themselves have reason to be grateful for it all.
William Pfaff is a syndicated columnist.