Tokyo is disappointed. Conservationists are delighted.

These are the two contrasting reactions after the highest UN court ordered Japan to stop whaling in the Antarctic.

In a case brought by Australia, judges at the International Court of Justice rejected Japan’s long-held claim that the catch is for scientific purposes and not primarily for human consumption.

Japanese Chief Cabinet Secretary Yoshihide Suga said Tokyo regretted the ruling but added that it would abide by it “as a state that places great importance on the international legal order and the rule of law as a basis of the international community. We are studying the content to see what we can do in a practical sense,” he said.

Some critics fear Tokyo may get round the ban by devising a new, more persuasive research project.

Conservationist group Sea Shepherd, which has clashed with whalers many times, wants the new ban to be enforced.

“The world is moving towards having a legal mechanism for protecting the global commons,” said Bob Brown, Sea Shepherd Australia’s Director.

“What is missing is the police force. We have got the court but we have no police. Now it is obvious that the United Nations has to establish an environmental police force to uphold the law.”

Japan signed a 1986 moratorium on whaling, but has continued to hunt up to 850 minke whales in the icy waters of the Southern Ocean, as well as smaller numbers of fin and humpback whales, citing a 1946 treaty that permits killing the giant mammals for research.

The new ruling does not stop Japan’s whaling activities in the northern Pacific.

While some Japanese view whale meat as a delicacy and an important tradition, consumers’ appetite for the meat has shrunk.