The Japanese government's decision to send the whaling fleet to the Antarctic defies a decision by the International Court of Justice in March that the hunting of whales in the numbers planned runs counter to Japan's international legal obligations. The court did not accept the excuse that whales were only being slaughtered for reasons of scientific investigation.

The Foreign Ministry must have been consulted before this decision was accepted. It must surely have drawn up a balance sheet comparing what Japanese interests would be damaged by such a decision and what the potential benefits were for Japan. Its submission to ministers has not been published and under the draconian secrecy laws may never be.

Japanese diplomats are professionals and competent. I guess that the balance sheet probably covered all of the following points.