Published by Jamie JemmesonIf Japanese policymakers are serious about intervening to bring the yen down from its recent 15-year highs, now is the time to act, according to Brown Brothers Harriman's Marc Chandler.Writing for Seeking Alpha, the investment group's global head of currency strategy said that while forex markets have been sceptical about the efficacy of a potential currency intervention, recent positive US data has given policymakers in Japan their window of opportunity.However, he went on to state that the country will keep out of the market for two reasons, the first being that their strategy would be based on the aim of "overwhelming the market in size", which would not be viable without international support."Secondly, Japanese officials are really at a loss and have little confidence," added Mr Chandler.However, he added that the yen will receive respite in forex trading this week."It will take a move back above JPY86 to cause the yen bulls to re-think and this does not seem likely in the near-term," he forecast.For more information on making international payments, visit our Smart FX site.