Not surprisingly, the LDP has greeted the DPJ’s “realism” with severe criticism.

Prime Minister Aso Taro suggested that the DPJ has become “blurred” by softening or reversing the positions it had taken on LDP foreign policy initiatives in recent years. Amari Akira, Aso’s minister responsible for adminstrative reform, also used the word “blurred” and suggested that “one cannot help but feel suspicious” about the DPJ. Ishiba Shigeru, the agriculture minister, said that the DPJ was making a mockery of elections by changing its positions in advance of the general election.

That LDP heavyweights have responded to the DPJ shift in these terms suggests that the DPJ may have made the right move. The LDP is effectively complaining that the DPJ has unfairly become a moving target, making it more difficult for the LDP to score easy points against the DPJ for being “naive” on foreign policy and putting Japan at risk for daring to question the wisdom of an ever closer US-Japan alliance. The LDP could naturally respond to the DPJ with a new Internet ad sarcastically welcoming the DPJ back into the LDP fold now that the party has seen the virtues of LDP foreign policies. But I remain convinced that the LDP has lost the foreign policy debate as a result of the DPJ’s tactical retreat: the LDP is hurt more by being less able to call the DPJ dangerous for its foreign policy positions than it is helped by the DPJ’s flip-flopping to “endorse” the LDP’s foreign policy plans.

But even as the DPJ moves to the center on foreign policy, it has to keep an eye on its potential coalition partners, which are emphatically not following the DPJ’s lead. The Social Democrats, for example, are calling for writing the customary three non-nuclear principles into law. Moreover, they have suggested that their conditions for a coalition government include at minimum preserving the three principles, abjuring from dispatching the JSDF abroad, and scrapping discussion in the Diet of constitution revision. In other words, there is the possibility of a serious (although not unexpected) rift with a party whose five votes help give the opposition parties control of the upper house. A DPJ-led government will need control of the upper house. If the DPJ cannot be assured of getting its laws through the upper chamber, it will be no less handicapped than the LDP has been since 2007. It is for this same reason that, should the DPJ win next month, the party ought to gear its plans towards winning enough seats in the 2010 upper house election to guarantee control of both houses. In the meantime, the DPJ cannot brush off the SDPJ so easily. The SDPJ will be able to drive a hard bargain simply because it has nothing to lose. With five members in the upper house and seven in the lower, it probably has more to lose from compromising its principles than from bending to the DPJ’s wishes. (Ladies and gentlemen, the single-member-districts-plus-proportional-representation electoral system!)

All of which leads me to wonder how far the DPJ can go with its pragmatic new foreign policy approach. Losing control of the upper house may be more harmful to a DPJ government than a spat with the Obama administration. At the same time, however, the SDPJ’s conditions may be easy for the DPJ to meet, at least in the first year. Japan has lasted this long with an ambiguous nuclear policy as far as the alliance is concerned — it can surely wait at least another year. I don’t think the DPJ will have any trouble pushing constitution revision off the Diet’s agenda completely. It may have a harder time assuaging the Social Democrats on the overseas dispatch of the JSDF, although perhaps a timeline for ending Japan’s maritime deployments — conveniently scheduled for after the 2010 elections — could buy off their support.

There is another challenge to the DPJ’s left, namely the challenge of what to do about the Communists. The JCP is using this election year to make some long overdue changes to its political strategy. For example, it will be running candidates in only 152 single-member districts instead of all 300. More recently, it declared that it will be a “constructive” opposition party, which in practice apparently means cooperating with a DPJ-led government on issues it supports and opposing it when its conscience demands opposition. In practice, the JCP’s new “realism” may make little difference for a DPJ-led government: on the issues that the JCP is likely to vote with a DPJ government, the SDPJ is likely to do so too. On foreign policy, however, the JCP is not altogether different from the SDPJ, and will likely provide encouragement to the Social Democrats should the DPJ try to buck them on foreign policy questions. The JCP may be ever so slightly softening its own opposition to the US — Party Chairman Shii Kazuo attended the US Embassy’s Independence Day reception earlier this month, for example, although this may not be too significant as it was the first time the JCP chairman was invited — but it is far from supporting the policies suggested by the DPJ in recent weeks.

It is too early to tell precisely what the JCP’s new realism will mean. The DPJ has to win first, after all. The JCP’s transformation, however, is certainly something to watch, as the DPJ, should it win, may need every vote it can find.