Japan's polite but pointed call for currency responsibility from South Korea and China has highlighted growing international tensions over exchange rates ahead of a summit of the G20 leading economies in Seoul next month.
Tokyo had previously refrained from even implied criticism of Seoul over currency issues, despite what traders say is the Bank of Korea's role in ensuring a cheap won that has given Korean exporters a big edge over their Japanese rivals.
That Naoto Kan, Japan’s prime minister, is willing to point a finger at South Korea will be seen as a further sign that G20 ministerial and leaders’ gatherings will be – as Nomura analysts declared recently – “the next major confrontation in the global currency wars”.