Prime Minister Junichiro Koizumi, in a speech to the United Nations General Assembly later this month, will express Japan's desire to become a permanent member of the Security Council. There is almost unanimous agreement that Japan should play a larger international role. This does not necessarily mean, however, that it should take a permanent seat on the council. Mr. Koizumi owes the Japanese people, as well as the international community, a convincing explanation of what Japan can and intends to do as a full-fledged member of the body.

The question touches the heart of Japan's foreign and security policy, yet there is little evidence that this has been discussed thoroughly within the government and the ruling parties. Mr. Koizumi should first have told the Japanese public in plain language why he believes Japan should seek a permanent seat.

The need to restructure the Security Council is widely recognized, although it has played a key role in the prevention and settlement of conflicts around the globe. It is effectively run by its five permanent members: the United States, Britain, France, Russia and China. They hold veto power -- a privilege not enjoyed by 10 nonpermanent members, which are elected by the General Assembly for two-year terms. Decisions by the council require the approval of nine of the 15 members, but we know only too well, a veto by any of the five can block action.