TOKYO -- First came the diplomatic niceties. Vice President Quayle told his host, Prime Minister Toshiki Kaifu, that it had been an honor and a pleasure to attend the Nov. 12 coronation of the Japanese emperor.

Then Quayle got down to business.

The world trading system is on the verge of crisis, Quayle warned Kaifu. Multinational trade talks appear likely to break down next month because the European Community is taking a hard line against opening its agricultural markets. The result of such a breakdown could be a surge in protectionism around the globe, perhaps even a trade war that could devastate the world economy.

Japan, Quayle said, should make a dramatic leadership move aimed at saving the talks, which are known as the Uruguay Round of the General Agreement on Tariffs and Trade (GATT). To do so, the vice president argued, Tokyo must take a step it has long known it would have to make eventually -- ending its ban on imported rice.

By offering now to open its rice market, Quayle said, Japan could prod the Europeans into being more flexible, thereby rescuing the talks from failure. That is something Tokyo should do everything in its power to achieve, he asserted, because it would help to preserve a trading system that has enabled the nation to prosper.

Quayle's plea, and similar requests from other U.S. leaders and officials in recent days, have forced Japan to confront once again an uncomfortable issue, one that might be called the nation's coming-of-age problem.

As it has grown to economic superpower status, Japan has found itself repeatedly challenged to take a global leadership role commensurate with its enormous financial clout. Yet showing such leadership has proven difficult.

In case after case, Japanese politicians have agreed only after prolonged pressure from allies -- typically the United States -- to take steps widely deemed to be in both Japan's and the world's interest, such as opening Japanese markets. Rather than take bold initiatives, Tokyo's consensus-minded policy makers prefer to wait until gaiatsu, or foreign pressure, becomes overwhelming; then they explain to aggrieved interest groups that gaiatsu is forcing them to act.

The coming-of-age problem was evident, critics say, in Japan's response to the Persian Gulf crisis. Weeks of pressure from the Bush administration, capped by furious denunciations in Congress, seemed to be required before the Kaifu government agreed to provide a $4 billion contribution to the gulf effort.

Now rice is emerging as a new test of Japan's international statesmanship. Some insiders confide that the government is seriously studying the idea of advancing a bold proposal at the trade talks. But the odds appear to be that Tokyo will respond as it has in the past -- which is to say it will cling to its policy of "not one grain of imported rice" until it absolutely has to let go.

In his meeting with Quayle, Kaifu was polite but noncommittal on the rice issue. But a senior politician in the ruling Liberal Democratic Party, asked if there is any chance that the government would make a dramatic concession on rice to save the GATT talks, replied bluntly: "No."

Japan, he said, "wants to see what kind of deal" -- if any -- emerges from the negotiations next month between the United States and the Europeans. Translation: Maybe the GATT talks will fall apart anyway, and Japanese politicians don't want to have to tell rice farmers that they made a concession before it was necessary.

"This says very sad things about Japanese leadership," said Ed Lincoln, a senior fellow at the Brookings Institution in Washington. "They have not yet gotten to the point where they can operate in a mode other than responding to fairly heavy foreign pressure. Even though they recognize that the GATT is important, that the Uruguay Round is important, and that their behavior is important for its success, they simply aren't able to push their own decision-making process in a way that looks like a leader."

Prime Beneficiary To be sure, the European Community, rather than Japan, draws most of the blame from economists and trade experts for threatening to cause the first failure of a GATT round of talks. The EC has offered only modest cuts in its farm protection program, infuriating the United States, Canada, Argentina and other major agricultural exporters.

But critics say Tokyo's failure to offer leadership is particularly disheartening because Japan has been one of the world's prime beneficiaries of the free-trade oriented regime fostered during the postwar era by the Geneva-based GATT.

Moreover, critics ask, since even Japanese politicians admit privately that a compromise on rice is ultimately inevitable, why not take the plunge now and get credit from the world community -- including the U.S. Congress -- for exhibiting a new degree of political maturity?

For years, Japan has been able to keep out imported rice, advancing the argument that a small, insecure island nation is required to maintain "self-sufficiency" in its staple food. Even though this meant that Japan's inefficient rice farmers could charge anywhere from three to 10 times the world price for their product, Japanese consumers complained little.

U.S. trade negotiators, meanwhile, left the closed rice market alone, recognizing that the issue stirs deep emotions among many Japanese and that rice farmers exert substantial influence over the ruling party because rural districts enjoy disproportionately heavy representation in the Diet, or parliament.

Even now, Washington is proposing to open the door gingerly to imports. Under the U.S. proposal, imported rice would reach just 5.25 percent of the market in 10 years, after which the quota would be replaced by a tariff.

But the difference today is that the once-unthinkable notion of importing rice has become seemingly inevitable. Perhaps more to the point, as former trade and industry minister Hikaru Matsunaga said earlier this year, "The idea of not importing a single grain of rice will not be acceptable to the world." Matsunaga was forced to apologize for making such a remark publicly, but its validity is widely conceded here.

Position on Hold Still, Japan appears determined to postpone the day of reckoning.

"We are not going to sacrifice our position," said the senior ruling party politician. He recalled the criticism the Liberal Democrats took three years ago from farmers for agreeing to open Japan's market to foreign beef and citrus fruits. Several major party figures lost their Diet seats as a result, he added, ticking off their names: "Mr. Eto. He's gone. Mr. Horinouchi, Mr. Yamanaka. Gone. Mr. Tamazawa. Disappeared."

Further decreasing the chances for a swift Japanese change in the rice policy is the fact that the government is suffering from a major drop in popularity as a result of its failure to obtain Diet approval for a bill to send a small contingent of soldiers to the Persian Gulf.

"It is very unlucky that Japan at this critical moment doesn't have powerful leadership," said Kenichi Ito, a professor of international politics at Aoyama-Gakuin University.

The government this week did begin to show signs of concern about the GATT talks. The cabinet pledged Tuesday to work for an agreement in the Uruguay Round talks scheduled to resume on Dec. 3, and several ministers publicly voiced fears about the specter of protectionism. But the cabinet also reaffirmed that, for now at least, Japan's rice policy remains unchanged.