"They've just come alongside the ship. They've put this grappling hook on the lower deck. They're knocking at the windows...They've pushed our cameraman over." With those breathless words, Greenpeace spokeswoman Stephanie Mills last week announced the start of a dramatic French military action near the South Pacific atoll of Mururoa. It was not the atomic blast the world had been anticipating, but the boarding of the Rainbow Warrior II by black-suited French navy commandos. Some three hours later, helicopter-borne troops slid down ropes onto the deck of a second ship, the MV Greenpeace, and then seized control.

The capture of the two vessels, the nucleus of a 25-craft "peace flotilla," left the militant environmental group with scant means to delay the seven or eight underground nuclear tests scheduled to begin at Mururoa this month. "I don't think Greenpeace will be able to mount another operation," said Vice Admiral Philippe Euverte, the French navy commander in the South Pacific.

But if Greenpeace lost the naval battle, it may be winning the public relations war. The French raids, which were broadcast around the world, added fuel to the international criticism--ranging from formal government protests to demonstrations and consumer boycotts--that has snowballed as the testing period has approached. "The French military has only one response to peaceful protest," said Greenpeace New Zealand spokesman Michael Szabo, "and that is to silence it and to use brute force."

The protests began last June after President Jacques Chirac announced that he was ending a three-year moratorium in order to carry out a "final" series of tests to ensure the credibility of France's "force de frappe." The trials were needed, he said, to verify a new generation of warheads and to perfect the computer-simulation technology that will allow France to forgo all live tests after May 31, 1996, and sign the Comprehensive Test Ban Treaty, which is due to be concluded late next year. Despite that pledge, Chirac's "irrevocable" decision has met widespread opposition at home and abroad. With more than 60% of his own countrymen opposed to the tests, the President has seen his poll ratings slide dramatically.

Last week's high-seas confrontation began Saturday at about 6 a.m. local time, when the Rainbow Warrior II sailed into the 12-nautical-mile exclusion zone surrounding France's nuclear-testing complex. With the navy frigate Prairial in close pursuit, the Rainbow Warrior II launched about half a dozen high-speed, inflatable craft bearing divers armed with waterproof radios and navigational equipment. Their mission: to board the test drilling rigs. French troops on the atoll immediately launched their own inflatable dinghies and intercepted the intruders. Two Greenpeace divers managed to drop into the central lagoon and reach an unused barge before they too were arrested.

Meanwhile, a French navy team boarded the Rainbow Warrior II with grappling hooks. As the crew members barricaded themselves belowdecks, the commandos sliced open the hatches with blow torches and forced their way in. After cutting radio wires and smashing radio equipment with a sledgehammer, the commandos took control of the engine room. The 20-minute raid was filmed by a Greenpeace helicopter, which circled over the exclusion zone for some three hours before landing on the deck of the nearby MV Greenpeace. Though the second boat never penetrated the zone, French commandos boarded and seized it shortly after the chopper touched down. Both ships were taken to Hao Atoll, 600 km north of Mururoa; their crews faced possible prosecution for "navigation in a restricted zone" and other charges.

Greenpeace officials immediately demanded the ships' release and appealed to New Zealand Prime Minister Jim Bolger to lodge a diplomatic protest. But there was little likelihood that the two vessels would soon be plying the waters of Mururoa. In the event of future intrusions, warned French Defense Minister Charles Millon, "the national navy and authorities will see that the security rules are respected." Coming from the country that 10 years ago sank the first Rainbow Warrior in a New Zealand harbor, that was no empty threat.