Their biggest enemy is of course not the nation that kidnaps ROK citizens, shoots ROK citizens in the back, sinks ROK naval ships, or even launches a artillery barrage against a civilian city:
Many teenagers think that the Republic of Korea’s greatest enemy is not North Korea but Japan, a study has found. The Korea Advanced Youth Association (한국청소년미래리더연합) and Teengora Media (틴고라미디어) surveyed 2,500 middle and high school students at over 400 schools nationwide, finding that although 63.5% believe that North Korea was responsible for the sinking of the Cheonan, 44.5% said that Japan is our greatest enemy, it was announced on June 23. (………)
Asked about enemies, 44.5% chose Japan, 22.1% chose North Korea, 19.9% chose the United States, 12.8% chose China and 0.6% chose Russia, showing that 44.5% of teenagers believe that Japan is an enemy. [Korea Beat]
There is more you can read at the the link, but I think what people need to draw from this survey is that Japan is ranked first because of the whole Dokdo nonsense while America continues to rank high in these type of polls because of the left wing teacher unions that I have long highlighted here at the ROK Drop.