Territorial and historical disputes between Korea and Japan have recently spilled over into an unexpected area ― U.S. soil. A wooden stake written with a slogan claiming Japan’s sovereignty over the Dokdo islets controlled by Korea was found at the entrance of the Korean consulate in New York on Saturday. A day before, a similar stake was spotted driven in beside a monument for Korean comfort women in Palisades Park in New Jersey.

A right-wing Japanese activist came forward Monday to claim his group had been behind the incidents. The 47-year-old man named Nobuyuki Suzuki angered Koreans in June when he attached a similar stake to a bronze statue of a young girl set up in front of the Japanese Embassy in Seoul to symbolize the suffering of Korean women forced into sexual slavery for Japanese soldiers during World War II.

What he should have known is that such acts would only soil the image of the Japanese as a whole. He may have attempted to strengthen Japan’s case in the historical and territorial disputes with Korea by attracting the U.S. public’s attention. But the shameful acts have only caused criticism in the U.S. and are certain to embarrass Japanese citizens with common sense. Even the Tokyo government, which has recently hardened its stance against Seoul in the rekindled dispute over Dokdo, may find them overstepping the line.

Driving in a stake beside the monument for Korean women coerced into wartime sexual slavery, in particular, is a disgraceful thing that denies Japan’s past atrocities.

We note that these embarrassing acts come against the backdrop of a series of remarks by Japanese politicians and officials who have refused to face up to the historical truth. Japanese lawmakers and diplomats have lobbied the municipal government in vain to remove the monument in return for economic rewards.

Right-wing Japanese politicians and activists should take a sincere note of testimonies by the victims and the international community’s sympathy with and support for them. International sympathy has led the U.S. Congress and legislatures in nine other countries to adopt resolutions condemning the wartime sexual slavery and demanding an apology from Japan.

The latest acts of vandalism would only exacerbate the international sentiment against Japan and heighten the historical barrier to building a partnership between Korea and Japan.

The incidents appear to have been accepted by Koreans more sensitively as Google Inc. recently deleted the name of Dokdo on its English-language Web mapping service, apparently influenced by Japan’s request to remove the Korean address of the islets. The government should strengthen efforts abroad to publicize Seoul’s position on historical and territorial issues with Japan ― in a decent manner.

U.S. judicial authorities should take necessary legal steps against the perpetrators. The Japanese government is urged to prevent its citizens from repeating such reckless acts in the future.