The results of a small town mayoral election on distant Okinawa island risks undermining plans to build a U.S. base and may further inflame tensions in the already strained U.S.-Japan military alliance. Challenger Susumu Inamine, who opposes constructing the U.S. base, beat pro-base Yoshikazu Shimabukuro in the January 24th contest, which had largely became a referendum on the U.S. military facility.

Inamine’s victory will stiffen Okinawan and Japanese resistance to the construction plan. Japanese Prime Minister Yukio Hatoyama will use the Okinawan election as further justification for refusing to abide by an existing bilateral U.S.-Japan agreement on the disposition of U.S. military forces in Japan.

In 2006, Washington and Tokyo agreed to a complicated realignment of U.S. forces in Japan, including Okinawa. The most contentious component was moving a Marine Corps air unit from a densely populated region of Okinawa to a more desolate location elsewhere on the island. Both countries agree that the Futenma Air Station needs to be moved due to safety concerns arising from urban encroachment on the base. However, plans to build a replacement facility near Camp Schwab faced opposition from local residents.

The left-of-center Democratic Party of Japan (DPJ), which assumed control of the Japanese government in August 2009, opposes the Futenma Replacement Facility (FRF) plan agreed to by the predecessor government. The DPJ has called for the U.S. to instead redeploy the Marine Corps air unit to Guam. The Obama Administration has strongly resisted the Japanese-proposed abrogation of the existing agreement. Washington correctly asserts that separating the Marine air and ground units would have detrimental impact on U.S. ability to fulfill its security obligations under the 1960 bilateral defense treaty.

Although the Nago mayor has little actual legal leverage over base construction, Inamine’s victory will be characterized as Okinawan rejection to accepting the redeployment of the Marine Corps air unit. The election decision could also intimidate the Okinawan governor, who faces reelection later this year, to hesitate in issuing the required environmental impact statement for expanding the base.

The election results will make it even more difficult for the DPJ to compromise with the U.S. on the FRF. The DPJ is reliant on two minor political parties to maintain a majority in the legislative upper house. Both of those parties have threatened to leave the coalition if Hatoyama implements the base agreement.

Hatoyama’s plunging approval ratings will make him even more reluctant to risking his administration in the run-up to the upper house election this summer. Ichiro Ozawa, the powerful DPJ secretary general, would strongly resist any attempt by Hatoyama to accept the advice of his defense and foreign ministers to implement the agreement.

Washington has become increasingly frustrated with Hatoyama’s indecisiveness and DPJ security policies. Regardless of how the FRF issue is resolved, there will be residual animosity in both Washington and Tokyo, complicating debate on other upcoming security issues. As a result, the U.S.-Japan military alliance will continue to be problematic during Hatoyama’s tenure.

Although the Okinawan election will make implementing the bilateral agreement even more difficult, the Obama Administration must remain resolute on the need to implement the force realignment agreement, especially maintaining U.S. Marine Corps air units on Okinawa. To garner increased Japanese support for the realignment plan, Washington should boost public diplomacy efforts to better educate Japanese officials and the populace on the necessity of forward-based U.S. forces to not only defend Japan but to also maintain peace and stability in Asia.

Despite its shortcomings, the alliance is critical to fulfilling current U.S. strategic objectives, including maintaining peace in the region. The forward deployment of a large U.S. military force in Japan deters military aggression by North Korea, signals Washington’s resolve in defending U.S. allies, and provides an irreplaceable staging area should military action be necessary.