Of all the issues that a new governor of a US state has to confront, one line in school textbooks would hardly appear to be the stuff of international showdowns. But Virginia's capital Richmond has turned into an unusual hotbed of diplomacy, with the ambassadors of Japan and South Korea both visiting in recent days to press in opposite directions on a proposed change in how textbooks describe the sea between the two US allies.

The move is the latest bid by Korean American activists to address historical grievances with Japan -- that rouse deep passions in South Korea -- at the local level in the United States.

Since 2010, cities in the New York and Los Angeles areas have set up statues in honor of so-called "comfort women" forced into sex by imperial Japan's soldiers.

While the statues also drew protests, Japan has devoted growing attention to Virginia, including hiring lobbyists to defeat the proposal, which would require textbooks to say "East Sea" -- the preferred term in Korea -- in addition to "Sea of Japan."

Peter Kim, a Korean-born businessman in Washington's Virginia suburbs who has championed the law, said he was horrified when he learned that his son was learning "Sea of Japan," a name that Koreans call a legacy of Japanese colonialism.

Kim launched a petition on the White House website but was told that state authorities determined textbooks.

"The Korean people have used the name for more than 2,000 years and even the Korean national anthem starts off with the East Sea," Kim said. "We are not politicians; we are citizens, we are moms and dads," Kim said.

"When I hear about the Japanese government trying to keep the name 'Sea of Japan' only, it brings old memories back and we say: 'hey, maybe they are trying to extend their history of military expansionism.'"

Masato Otaka, minister for public affairs at the Japanese Embassy, said it was important to teach accuracy and that "Sea of Japan" was the only name recognized by the United Nations and the International Hydrographic Organization.

"Sea of Japan" was already in common usage in the world in the early 19th century, when the country had an isolationist policy, Otaka said. At the time, "there was no Japanese colonial rule, and Japan could not have influenced other countries to use this name," he said.

David Marsden, a state senator who took up the issue in response to his constituent Kim, said he was not trying to change US government usage of "Sea of Japan" but wanted to recognize the views of Virginia's growing Korean American community.

"I think the Japanese government has kind of overreacted to this. This is not that big of a deal," the Democratic lawmaker said. Growing number of battlegrounds

The Virginia battle presents an unenviable choice for the state, where Asian Americans are increasingly seen as a critical voting bloc for President Barack Obama's Democratic Party but where Japan is by far a larger trading partner, investing nearly $1 billion in the past five years -- second only to Germany.

Governor Terry McAuliffe, a Democrat, and his rival in last year's election both supported the textbook change as candidates. But McAuliffe is by all accounts uneager to be sent the legislation, which has passed the Senate and awaits House action. Elsewhere, Georgia's state Senate recently passed a resolution that, amid anodyne language praising US relations with Seoul, describes the Korean Peninsula as "bound by its East and West Seas."

The controversies have risen at a time of high tensions between South Korea and Japan over historical disputes. But Korean American activists say impassioned individuals have led movements and that there is no overarching national strategy. Local political decisions with foreign policy ramifications are not unprecedented in the United States.

Forty-two of the 50 US states have described the mass killings in 1915 of Armenians as "genocide" after campaigning by Armenian Americans, whose efforts at the federal level have been thwarted by fierce opposition by Turkey.

Japanese Americans are nearly as numerous as Korean Americans but mostly immigrated before World War II, when the US government interned them en masse. A number of Japanese Americans, most notably US Representative Mike Honda, have supported criticism of Japan on historical issues.

Michael Green, who served as former president George W. Bush's top adviser on Asia, told a conference of South Korean and Japanese students that he had mixed feelings on Tokyo's attempts to block local initiatives but increasingly believed that the efforts served a purpose.

"Whatever you think of the merits of the case, it's important for state legislators and others to understand these are not cost-free things you can do for a local constituency. They have some foreign policy implications," he said.