NAHA, Japan -- There's a joke on Okinawa that holds American Marines would be flying out of new runways by now if only Japan could build military bases as fast as China sprouts new islands in the South China Sea.
It's a dark reminder that the Marines are based there in part out of fears that China's expansion may threaten Japan.
Instead, Tokyo's long-delayed plan to relocate a Marine airbase on this southern Pacific island has stalled for 19 years in the face of fierce environmental protests aimed at protecting a clear-blue harbor called Oura Bay.
The impasse has American helicopters flying out of a different Okinawa base, Marine Corps Air Station Futenma, that's been marked for closure since 1996 because of its location in a densely populated city.
Leaders insist that moving the aircraft to Camp Schwab on Oura Bay is the "only solution" to resolve the festering problem over what to do with Futenma. Yet that plan looks as stalled as ever.
Here are five reasons why that stalemate likely will persist well into the next decade:
It's too complicated
In the best circumstances, laying Marine runways into Oura Bay off of Camp Schwab will take years to complete. That buys time for activists to derail construction, for Japanese voters to change political leaders or for American lawmakers to change their minds.
Auditors at the Government Accountability Office last year likened the Camp Schwab plan to a similar offshore runway that Japan recently built for U.S. forces on a different island. That runway for Marine Corps Air Station Iwakuni took 13 years to complete and cost Japan more than $2.5 billion.
That's a long time and a lot of money for a project as controversial as the one proposed for Oura Bay.
The Marines like what they have
Marine Corps Air Station Futenma is far more valuable military real estate than the runways that would replace it.
Futenma's runway is the only one on Okinawa that sits at a high enough elevation to survive a tsunami unscathed.
The civilian airport in Naha is at sea level and would be knocked out. Even the Air Force's powerful Kadena Air Base north of Futenma would be impacted by flooding.
If the Marines move to Oura Bay, their runways will be at sea level, too.
The runways proposed for Camp Schwab also are significantly shorter than the one at Futenma. Futenma's stretches for 9,000 feet and can handle the largest military aircraft.
The ones on Oura Bay would be about 5,900 feet, tailored more for helicopters and tilt-rotor Osprey aircraft than the large jets that would be tapped for a war or serious natural disaster.
Every day, a group of mostly white-haired protesters stands outside the gates of the Marine base that would host the new runways.
Some are native Okinawans who want a smaller military footprint on their homeland. Others are visitors from faraway provinces lending support to the cause.
"Military bases are so bad for the Okinawan people," Guyoken Kuroyanaga, 62. He's a Buddhist monk who moved to Okinawa from mainland Japan just to protest the Marine plan. "There is no freedom for the Okinawan people here."
If construction starts, protesters might be willing to interfere with workers. That's why a legion of police officers watches the camp every day and security boats patrol the waters of Oura Bay to keep outsiders away from Camp Schwab.
But the protesters aren't going anywhere.
Okinawa's new governor came into office with a mandate to undo any progress Washington and Tokyo had made on developing the runways at Oura Bay.
Since then, he's stalled Prime Minister Shinzo Abe's bid to start construction and railed against the plan to the United Nations. Onaga's campaign is drawing support from wealthy Okinawans, who've raised more than $4 million in an organization called the Henoko Fund to block the Marine proposal.
Onaga's making a popular case that Tokyo is trampling on the right of Okinawans to determine their own futures. It rings true for Okinawans who think of themselves as carrying a disproportionate share of the American military presence in Japan.
"Our right to self-determination and human rights have been neglected," Onaga said at a United Nations forum in September. "Can a country serve values such as freedom, equality, human rights and democracy with other nations when that country cannot guarantee those values for its own people?"
It may disrupt a good thing at Camp Schwab
Okinawans are commonly depicted as uniformly anti-military, but that stereotype obscures broad differences in how individuals view American Marines.
In fact, the daily anti-Marine protest that takes place outside Marine Corps Air Station Futenma often draws a parallel group of Okinawans who show up with banners thanking American troops for their military service.
The village next to Camp Schwab, Henoko, is especially fond of Marines. It reserves a seat on its town council for the Marine base and its residents often participate in games with the troops.
Some fear that dynamic could change if loud Marine helicopters and Osprey aircraft start landing at Camp Schwab, disturbing residents who in other circumstances would back the military presence.
Yoshimasa Shiroma, 85, has been serving sushi to Marines at his Henoko restaurant for 42 years. They're his customers, and he loves them.
He wouldn't give his opinion about whether the runways should be built, but on a swampy night with a restaurant full of brawny Marines, Shiroma said he doubted the plan would ever happen.
"As long as I'm alive, I don't think it will be built," he said.