Martin Fackler, An Icon and a Symbol Of Two Nations’ Anger, New York Times, June 3, 2013
(the current government in Seoul does not make any official claim to Tsushima)
Note:
(a) "an ancient Zen temple [in Island of Tsushima] that sits in the shadow of stone fortifications used by a Japanese warlord to invade the Korean Peninsula in the 16th century."
Japanese invasions of Korea (1592–98) http://en.wikipedia.org/wiki/Japanese_invasions_of_Korea_(1592%E2%80%9398)
(two invasions; also known as 文禄・慶長の役 (in Japan) and 萬曆朝鮮之役 (in Taiwan); led by TOYOTOMI Hideyoshi 豊臣 秀吉; Result Korean-Chinese victory; Withdrawal of Japanese armies)
(b) "local residents [on Tsushima] say they have gathered annually for most of the last seven centuries to commemorate a battle in which a small band of samurai was wiped out trying to stop a Mongol-led invasion fleet from Korea"