Russia's government has started an unwinnable war against the environmental lobby Greenpeace, which has a long history of defeating governments that try to stop its protests by brute force.

Greenpeace activists on their ship the Arctic Sunrise tried to board the Russian natural gas monopoly Gazprom's giant Prirazlomnaya oil rig last week, only for 30 crew members and passengers to be arrested on piracy charges. They should have known what was coming. A Greenpeace team had already boarded Prirazlomnaya in August last year, braving the crew's fire hoses, and erected tents on a drilling platform. Soon afterward, a rambling anonymous comment, apparently from a Gazprom functionary who witnessed the boarding, appeared on Greenpeace's Russian-language website.

"People in gaily colored boats break into the 500-meter security area," the posting said. "No matter how these people are dressed, what kind of face paint they are wearing, what they are shouting and waving, they try to get on board. Who are they? What are their intentions? To seize? To attach a bomb? To install a tracking device so weapons can be aimed?" And finally: "The platform is a vessel, and getting on board without the captain's permission may and in this case should be viewed as piracy."

Prirazlomnaya has been plagued with technical mishaps and the start of drilling has been delayed several times. Greenpeace insisted the rig was unsafe and attempted a second boarding on Sept. 19. This time they ran into stiffer resistance: Russian coast guards fired over their heads and towed the Arctic Sunrise to Murmansk, where the 30 people who had been on board were detained. On Sept. 26 and 27, a Murmansk court arrested them for two months on suspicion of piracy.

Soon after the Russian authorities first indicated that piracy charges might be brought against the activists, President Vladimir Putin essentially repeated arguments from the anonymous comment. "Our border guards, our law enforcement agencies did not know who was trying to seize the rig posing as Greenpeace," he said, adding: "It is perfectly obvious that they are not pirates." Yet the court went ahead with the arrests. Putin has a history of publicly favoring clemency towards various detainees, such as members of the Russian opposition, without any effect on their actual treatment at the hands of the law enforcement authorities or courts. Asked to comment on this apparent disobedience, Putin is apt to shrug and point out that the courts and police do not formally report to him.

The piracy charges are unprecedented and likely to be lifted, eventually. Yet the show of force is clearly meant to intimidate Greenpeace, so that it will think twice before continuing to pester Gazprom -- it is not as though this were the first time. Activists have picketed the monopoly's Moscow office, harassed exploration ships in the Arctic and generally made themselves a nuisance. Gazprom is a state-controlled mainstay of Russia's hydrocarbon economy, and the government is, effectively, issuing a warning to activists to keep away from it.

The opposite effect is more likely. Arctic Sunrise was captained by Peter Willcox, former captain of the Rainbow Warrior, the Greenpeace ship that was sunk by French agents in New Zealand in 1985, after being used in protests against nuclear testing in the Pacific. Greenpeace fought the French government for damages and won an $8 million award from an international tribunal.

In 2007, six Greenpeace activists climbed the chimney of the Kingsnorth coal power plant in the U.K. and tried to paint the prime minister's name down its side, hoping to draw attention to their campaign to have the plant closed down. They were accused of causing criminal damage to the property but acquitted in 2008, on grounds that they had been attempting to prevent greater damage to the environment.

Greenpeace boasts many such victories: It is a tenacious, well-funded organization with millions of supporters worldwide. In a sense, it is a tougher rival for Russia than many governments. Trying to scare it into inaction makes no sense from a public relations perspective: The ridiculous piracy charges, for example, are likely to erode the international credibility Putin recently gained by persuading Syria to sign up the Chemical Weapons Convention, thereby preventing U.S. airstrikes.

Besides, the Greenpeace protesters are hardly a threat. When Greenpeace volunteers dressed as polar bears boarded a Statoil rig in April 2013, they were escorted ashore after spending three hours on the platform chatting amiably with the crew. The Norwegian oil company said it did not want to take any legal action, and everyone went peacefully about their business. Gazprom should take a cue from its Nordic counterpart and call off the dogs.

(Leonid Bershidsky, an editor and novelist, is a Bloomberg View contributor. He can be reached at bershidsky@gmail.com).