Former Deputy Foreign Minister Chun Yung-woo warned an American official in 2010 that revising the Nuclear Cooperation Agreement could soon become a “defining issue” in South Korea-US relations, and that it was already attracting “significant amounts of negative press attention.” Given South Korea’s status as one of the world’s top five nuclear-power producers, Chun argued, the South Korean public would not tolerate the perception that Japan was receiving preferential treatment.