THE FRENCH government has now made the astonishing admission that its secret agents, acting under orders, sank the Greenpeace ship in a New Zealand port on July 10, killing one person aboard. The confession follows a long hot summer of official denials in which a government investigator and, to take him at his word, the defense minister himself were deceived about the French role. Not even the resignation of the minister and the firing of the admiral who runs the secret services could staunch rising demands that the full truth of this episode be told. A parliamentary investigation is due to be added to the government's own inquiries, and to inquiries conducted by the press. The key unanswered question is just who ordered the mission.

The political community is vigorously maaging the question of how this scandal may affect legislative elections coming up next March. Currently Francois Mitterrand's Socialists control the National Assembly, but the Greenpeace affair has damaged the president and allowed a ready and restive right to renew challenges to both his personal governance and the Socialists' claim to be reliable on issues of national defense. The French system is poorly constructed to deal with a president and government of one party and a parliament of another, and so there is an inevitable political quickening now.

What is more startling to Americans is the object of the public protest in this affair. A commentator in Le Monde observed that there had been "not a squeak" about the actual mission, which New Zealand's government describes as "a squalid example of state-sponsored terrorism," about the violation of the sovereignty and good faith of a friendly state, or about the loss of life and property that resulted. Nor is there much evident concern that French intelligence may have been acting as a rogue elephant, roaming beyond even secret official control.

There has been no nuclear debate to speak of in France. The French nuclear force enjoys support across the political spectrum: the left, always somewhat suspect in the eyes of some on the right, has been under special pressure to support this symbol of French independence. In this sphere, the state is widely accepted as an actor removed from public accountability.

Rather, the public is aroused over the spectacle of official clumsiness and lying and the subsequent impact on national dignity and credibility. So it is that Mr. Mitterrand can get away with saying that those, like Greenpeace, who oppose French nuclear testing are "adversaries" of France. It is much harder to get away with looking as though he cannot run his government.