Behind Prime Minister Yukio Hatoyama’s stalling on the future of U.S. Marine Corps Air Station Futenma in Okinawa Prefecture seems to lie a long-held wish to reduce the presence of U.S. forces in Japan, as well as the determination of his former boss, Ichiro Ozawa, to keep a grip on the Diet.

Hatoyama, president of the ruling Democratic Party of Japan, has put on hold a decision on the Futenma air station’s relocation following a threat by Mizuho Fukushima, leader of the Social Democratic Party, a junior partner in the ruling coalition, to leave the government if the DPJ goes ahead and moves the base within the prefecture under an existing Japan-U.S. deal.

Hatoyama is placing more emphasis on maintaining power in the Diet than on improving the soured relationship with Washington, which has pressed Japan to resolve the matter quickly and move the Futenma base in line with a 2006 accord.

The DPJ, which won a landslide victory in the August Lower House election, had to form a coalition with two smaller partners, the SDP and Kokumin Shinto (People’s New Party), despite differences over security and foreign policies, as it requires their cooperation in the House of Councilors.

Speculation is now growing that a decision on the U.S. base issue will not be made until after next year’s Upper House election, in which the DPJ is widely expected to secure a majority, enabling it to break free from what appears to be an awkward coalition.

Political observers say that behind the delay is DPJ Secretary General Ozawa, who is widely believed to have wielded his influence behind the scenes over the Hatoyama government since its launch in mid-September.

According to sources close to Ozawa, he has pressured the prime minister’s office and Defense Minister Toshimi Kitazawa to deal with the relocation issue in a way that would not result in the collapse of the coalition.

Eiken Itagaki, an independent political analyst well-versed in DPJ politics, said that Ozawa warned that the government needs to avoid the previous difficulties the Liberal Democratic Party-led government experienced in a divided Diet.

But there is also a view among some analysts that Hatoyama simply used the coalition partner’s threat as an excuse for delaying a decision, as he himself hopes to move not just the Futenma air station but also the entire U.S. military facility outside Okinawa, or even outside the country, and wants to take time to find a better solution.

Hatoyama repeatedly made comments to that effect while the DPJ was in opposition.

“I truly wonder if it is appropriate that a military of another country will continue to station in this country forever,” he said a few weeks after taking office.

Kazuhiro Asano, professor in politics at Sapporo University, said that if the DPJ kicks the SDP out of the coalition after the Upper House election, “I don’t think Prime Minister Hatoyama will decide to move the Futenma facility to Henoko.”

Under the 2006 deal, Tokyo and Washington agreed to transfer the Futenma air station, which currently sits in the center of a residential area in the city of Ginowan, to the coastal area of the Henoko district in Nago, in northern Okinawa, by 2014.

Hatoyama has indicated that he wants to wait and see the results of the Nago mayoral election scheduled for January to determine the will of local voters before making any decision on the relocation.

“He is looking for evidence and reasons that would help him decide to move the base outside the prefecture,” Asano of Sapporo University said.

Ozawa, a former DPJ chief, is also against hosting another country’s military in Japan. Analyst Itagaki said both Ozawa and Hatoyama are seeking a foreign policy stance that depends less on the United States and more on close relationships with other countries including China and Russia, as promised in the party’s campaign manifesto.

Ozawa once expressed the view that the role of the U.S. military in Japan should be reduced, saying the U.S. Navy’s 7th Fleet based in Yokosuka would be “enough for the U.S. presence in the Far East.”

At the bottom of it, the foreign policy that Ozawa and Hatoyama are pursuing over the long term is not so different from that of Fukushima, chief of the pacifist, leftist SDP, Itagaki said, suggesting that the DPJ may end up keeping the party in the coalition even after the Upper House election.