As the Japanese government approaches its self-imposed deadline to determine the fate of the Marine base on Okinawa, some foreign affairs experts doubt that a deal favorable to the U.S. is possible.

Patrick Cronin, senior director for the Asia Pacific Program at the Center for a New American Security, said the ambitions of Prime Minister Yukio Hatoyama's Democratic Party to dominate upper-house parliamentary elections in July will require rewriting promises their predecessors made about the base relocation in 2006.

"I think the Obama administration has serious doubts as to whether his government can deliver and implement this," Cronin said. "The Democratic Party of Japan remains chaotic.... Every policy utterance is being put through the election prism, which is seldom helpful for negotiation. A coalition of their smaller opponents is against the bases in Japan altogether."

Marine Corps Air Station Futenma has been a sore spot for its neighbors due to concerns about crime and pollution. The 2006 agreement promised to relocate Futenma to Camp Schwab, an existing Marine base near a tiny fishing village at the north of the island, where a runway would be constructed. Cronin said there are many ideas being tossed around as alternatives, but the runway seems unlikely.

"You might get a new heliport rather than a new runway that would supposedly damage the ecosystem there that the previous administration promised," he said. "They might even put some of the operations at a Japanese Self-Defense Force base."

To help placate Okinawa residents, Japanese defense official Akihisa Nagashima has mentioned the possibility of compensating them, which Cronin said is likely. "The central government is going to have to buy out some more support in Okinawa for the national good," he said. "You're dealing with a highly polarized issue, and it's in the interest of both Japanese parties to find a solution quick and limit the impact of the decisions. They've shown they couldn't reach a consensus and that they couldn't make a quick transition to an opposition party to a ruling party."