SIX tonnes of elephant tusks and ivory trinkets were destroyed in a tarmac crusher in the factory city of Dongguan in China on January 6th. Most of the 33-tonne stockpile of Hong Kong-home to many of the world's most avid buyers of ivory-as well as those of several European countries will soon meet the same fate. In the past few years ivory has also been destroyed in the United States, Gabon, Kenya and the Philippines.

These scenes lack both the curling smoke and dramatic setting of the vast pyre of tusks burned in Kenya's Nairobi National Park in 1989. (Most ivory is now destroyed by crushing, rather than burning, to avoid polluting the atmosphere.) But they may prove equally significant in the long fight to stop poaching and save the elephant from extinction.

The bonfire near Nairobi was the prelude to a global ban on trade in ivory, a collapse in demand and a lull in poaching that gave the African elephant population time to recover. But in the past five years poaching has picked up again. An estimated 25,000 elephants are killed each year by poachers, many of them linked to organised crime. In some places the species is close to being wiped out.

Hopes are high that a conference on the illegal wildlife trade in London on February 13th will give the coalition against ivory poaching new impetus. Links between ivory traffickers and African militias such as the Lord's Resistance Army, a thuggish band of guerrillas that originated in Uganda, have put the issue on the national-security agenda in America and elsewhere. The result is attention from political heavyweights including Bill and Hillary Clinton; John Kerry, America's secretary of state; and David Cameron, Britain's prime minister. African governments have agreed to to beef up park patrols, create anti-poaching police units in the states where elephants roam and strengthen anti-poaching laws. The measures have so far been underfunded. Making them stick would cost an estimated $300m over ten years, much of which it is hoped will come from the rich countries at the conference.

Though campaigners welcome the plan they argue that curbing the supply of ivory is not enough. Since 1989 countries with elephant populations have twice been allowed to sell stockpiled ivory from elephants that died naturally under CITES, a global agreement on international trade in endangered species. Before the second sale, in 2008, conservationists warned that it would revive the market in China, where ivory ornaments have long been prized, and make poaching profitable once more. They were right. The ivory bought by the Chinese government is drip-fed onto the domestic market at a rate of five tonnes a year. That comes nowhere close to meeting demand, estimated at 200 tonnes a year. And the sales have coincided with an explosive increase in poaching.

Governments should destroy their stockpiles and ban the sale of ivory from any source, argues Alex Rhodes of Stop Ivory, a group that is raising money for the anti-poaching plan. Legal sales not only stoke demand, but create ambiguity about the legal status of all ivory, providing cover for the sale of poached items.

Peter Knights of WildAid, another lobby, compares ivory trafficking to the drugs trade. Enforcement is a losing battle, he says, and the only way to end poaching is to choke off demand. Yet a ban on ivory sales combined with clever advertising might work. A campaign supported by stars to wean Chinese consumers off shark fin nudged their government into dropping it from state banquets. Overall demand for the traditional delicacy has since fallen by half.