Japanese Prime Minister Junichiro Koizumi has been one of President Bush's strongest supporters on the international stage, and Iran is certain to be high their agenda when the two leaders meet today. But Japan's support for U.S. policies could change when Mr. Koizumi steps down in September.
Tokyo was not a party to the incentives offered to Iran in exchange for an immediate suspension of uranium enrichment. But senior Japanese officials have worked closely with their U.S. counterparts in recent weeks, and Mr. Bush has urged Mr. Koizumi to support the view that Iran must terminate its nuclear program.
Secretary of State Condoleezza Rice appealed to Japanese Foreign Minister Taro Aso for cooperation in resolving the standoff, and Mr. Aso is reported to have communicated directly with his counterpart in Tehran. But Japan's unique role is not always appreciated. Japan's Daily Yomiuri newspaper quoted an unidentified senior U.S. government official as saying that Japan is being too soft on Iran because it attaches too much importance to its economic interests.
These economic interests are considerable. Japan is Iran's third-largest trading partner and the leading consumer of Iranian oil.
For now, Japan is curbing its crude oil imports from Iran in anticipation that a diplomatic standoff could cause supply disruptions. But Japan does not have a formal plan for dealing with a protracted disruption. Nearly 90 percent of its oil originates in the Middle East, and at current consumption levels, Japan's 90 million-barrel strategic reserve would last for only four months.
Japan has even more specific interests in Iran. Its energy company, Inpex, is under contract to develop the Azadegan oil field, believed to be the largest in the world, but work on the project is stalled. Company officials have cited security concerns posed by land mines in the area, which is situated along Iran's border with Iraq, but there is speculation that they are biding their time, waiting to see how the negotiations over Iran's nuclear program proceed before spending hundreds of millions of dollars on the project.
Financial sanctions are not likely to persuade Iran to abandon its nuclear ambitions, and the Bush administration knows that any such measures will depend heavily on Japanese participation. For now, senior Japanese officials are expressing skepticism.
Chief Cabinet Secretary Shinzo Abe, a leading candidate to replace Mr. Koizumi as prime minister, said this month that sanctions "might not damage Iran but could cause confusion in the world economy."
Japanese policymakers are reluctant to sign onto an economic boycott of Iran unless it has strong international backing. Mr. Aso told Reuters that Japan would support international sanctions but warned that talk of such measures was premature. He stressed that sanctions would require "concerted action" by "everyone."
The worry: Japan could end up withdrawing its economic stake in Iran only to have another country's oil companies rush in to take its place.
Japan is particularly leery of China gaining a foothold in Iran. Accordingly, the Japanese are seeking a broad international consensus, such as a U.N. Security Council resolution. They likely will demand that China and Russia be part of the deal; a pledge to "not veto" sanctions might not be good enough.
Japanese Finance Minister Sadakazu Tanigaki hesitated when U.S. Treasury Secretary John W. Snow asked him to consider a range of sanctions against Iran. Like Mr. Aso and Mr. Abe, Mr. Tanigaki is expected to compete for prime minister, and he would say only that any move to impose sanctions against Iran would need to be discussed "more broadly with Europe and others."
This comment is in stark contrast to Mr. Koizumi's support for the Iraq war and suggests that the pattern displayed with respect to Iraq - when Mr. Koizumi defied popular opposition in Japan to back Mr. Bush's policy - will not be repeated if there is a confrontation with Iran.
A U.S. decision to go it alone would strain U.S.-Japan relations, so carefully cultivated during Mr. Koizumi's tenure as prime minister. The potential costs are considerable.