For 17 years, the U.S. and Japan have been haggling over a Marine base in Okinawa.

On Friday, the problem was solved, as the governor of Okinawa prefecture approved a permit to begin construction of a relocated base in a less-populated area, breaking tensions that have persisted since the 1995 rape of a Japanese girl that reanimated opposition among residents to the presence of Marine Corps Air Station Futenma.

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With the final legal hurdle cleared (despite opposition from residents in Nago, where the new base will be built), Japan will construct the new air base, and the Pentagon says it expects U.S. troops to move there in 2022, U.S. and Japanese officials said.

There is some optimism that the construction permit has cleared a logjam for President Obama's strategic Asia "rebalance"-an oft-advertised, if not-so-often evidenced, refocusing of U.S. diplomatic and military attention on that continent, away from a decade-long mire of conflict in the Middle East and Afghanistan.

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Japan is a key ally in Asia, and the planned base relocation could ease tensions and free up time for diplomats and military officials-some of whom have worked on the Futenma issue for 17 years-to look ahead at broader strategic problems.

"This issue has sucked a lot of oxygen out of the alliance management for too many years," a Japanese official said, calling the base "one of the biggest issues between Washington, D.C., and Tokyo" at times in years past. The U.S. and Japan can move onto more "future-oriented work," the official said.

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Among those future-oriented issues are Chinese territorial expansion, as seen in the recent announcement of an air-defense identification zone (ADIZ); maritime issues; the threat of North Korea; trilateral cooperation with Japan and South Korea, two nations at odds with one another, but which share a U.S. interest in North Korean containment; and negotiations for a Trans-Pacific Trade Partnership (TPP). All of those are major elements of U.S. strategic maneuvering in Asia, and all require work with Japan.

Realigning U.S. forces in Japan is seen as "the spine of the rebalance" to Asia, a senior U.S. defense official told reporters on a conference call Friday. "It will free up a lot of senior-level attention," including that of President Obama, Hagel, Kerry, and their Japanese counterparts, the defense official said.

A "seemingly unsolvable" problem, the Futenma base has been a "real thorn in the side of the alliance relationship," said Sheila A. Smith, an Asia-Pacific expert and senior fellow for Japanese Studies.

"What our government now wants to do is focus more broadly on a host of strategic issues between the U.S. and Japan that include not just force posture issues, but how do Japan and the U.S. understand the changing strategic environment in Asia," Smith said.

The relocation of Futenma will allow 9,000 U.S. marines to move off Okinawa, with 5,000 of them moving to Guam, the Associated Press reported, fulfilling another element of the "rebalance," according to Smith: a more dispersed U.S. military posture in the region, with Marines able to respond more readily to humanitarian/environmental disasters and in the event of conflict between North and South Korea.

The relocation of Marines is "absolutely critical to the United States' ongoing rebalance to the Asia-Pacific region and our ability to maintain a geographically distributed, operationally resilient, and politically sustainable force posture in the region," Defense Secretary Chuck Hagel said in a statement Friday.

Rolled our in 2011 as a "pivot" and later rebranded as a "rebalanced," the proclaimed strategic shift has at times appeared to be more wishful thinking than reality. The U.S. remains undoubtedly focused on the near East and southwestern Asia, as its major diplomatic and military projects are, currently, the war in Afghanistan, an interim nuclear deal with Iran, deteriorating security in Iraq, civil war and chemical-weapons destruction in Syria, and faltering peace negotiations-and faltering peace-between Israelis and Palestinians. More recently, the U.S. has given high-level diplomatic attention to Africa, as the world confronts widespread violence and death in the Central African Republic and South Sudan.

But if the "rebalance" is to proceed, at least officials on both sides agree that a preliminary hurdle has been cleared.