YONAGUNI ISLAND, Japan — For years it was known as the "Two Gun" island – one gun for each of the two policemen stationed here.
Yonaguni, Japan's most westerly island, can feel like a peaceful paradise — it is covered in tropical forests and hammerhead sharks glide through its azure waters.
But there is trouble on the horizon. Almost 70 miles away lies the island of Taiwan — the self-governing democracy which once again finds itself in the headlines.
On Thursday, six Chinese ballistic missiles landed in water near Japan's southwestern islands, one of them near Yonaguni and five others within Japan's Exclusive Economic Zone, according to the Japanese authorities.
The missiles were part of large-scale military exercises China is conducting in response to House Speaker Nancy Pelosi's overnight trip to Taiwan this week. She is the highest-ranking elected U.S. official to visit the island in 25 years.
China sees Pelosi's trip as a show of support for Taiwanese separatist forces. In the past, Beijing has threatened to invade the island, if it declares independence.
The roughly 1,700 inhabitants of Yonaguni now fear that their island could be on the front line of any conflict.
"During the Vietnam War, boat people came here," says Ryuichi Ikema, the director of a history museum on the island. "In case of a Taiwan contingency, millions of Taiwanese could come here. We're the closest island, and I wonder: how can we deal with it?"
For centuries, Yonaguni was part of the semi-independent Ryukyu Kingdom, a tributary state of China and Japan. It did not become a part of the modern Japanese state until the late 1800s. For a half-century, until the end of World War II, Taiwan was a colony of Japan and trade between Taiwan and Yonaguni flourished.
But every year, Yonaguni residents mark the anniversary of the end of the World War II battle for the nearby island of Okinawa. Nearly a third of Okinawa's population died in the fighting, and that contributed to a strong sense of pacifism on Yonaguni.
China's rise has changed the equation. Japan has been strengthening defenses across its southwest islands, which form a series of choke points between the East China Sea and the rest of the Pacific Ocean.
In 2016, the government built a military base on Yonaguni and stationed about 160 soldiers on it, tasked with monitoring waterways and airspace.
The island is divided on the military presence. Masateru Nakazato, who teaches at a local school and whose students include children of soldiers at the base, says his students sometimes ask him what would happen in case of a conflict over Taiwan.
"I tell them, that's why we have the self-defense forces," he says, referring to Japan's military. "They will protect us. And America will protect us."
Nakazato's wife Yuka, though, believes building the base has damaged the island's natural environment and has contributed little to the local economy.
"I've never felt having the base here makes us safer," she says.
Japan's sense of a growing threat from China has also led to a historic shift in Tokyo's thinking about Taiwan.
Last year, Japanese officials began publicly linking Taiwan with their own security. Some argued that if China invades Taiwan, the U.S. and Japan should defend Taiwan together.
Masahisa Sato is a lawmaker and director of the ruling Liberal Democratic Party's foreign affairs division. He says that if China attacks Taiwan, Yonaguni and other nearby islands could become targets.
"It is actually important for China to attack the island of Taiwan from both sides," he says. "If they attack from the east, Japan's southwest islands will become a battlefield."
Japanese media have reported that the U.S. and Japan have drafted a joint military operational plan to respond to an attack on Taiwan. But Yoji Koda, a former commander of Japan's Maritime Self-Defense Force Fleet says that Japan's pacifist constitution makes such a plan a political long shot — and progress appears to have stalled.
"If your question is: Do the U.S. and Japan together have a joint or combined operational plan, the answer is no," he says.
Back on Yonaguni island, local officials are moving ahead with plans of their own.
"The town has already decided on an evacuation route within the island," says Toshio Sakimoto, head of the town's assembly. "We have asked the prefectural and central governments how to get residents to safety from there."
The central government, he says, "didn't reply for a long time, until June, when Taiwan became an issue, and they began to think about putting the evacuation issue on the table."
The plan, Sakimoto says, is to get all the island's population to its airport and harbors within three days of authorities receiving news of threats.
Where they'll go from there, he says, remains unclear.
Chie Kobayashi contributed to this report on Yonaguni island and Tokyo.