Japan's intervention since April has helped to slow yen decline against the dollarHave not received nay objections from the US against Japan's intervention since thenJapan-US currency coordination remains closeSure, sure. They still have put up a facade to maintain that illusion that they are well in control of the situation. But considering how traders quickly brushed aside their intervention efforts and we're now seeing USD/JPY hit 40-year highs after, it says a lot about the current predicament.If they intervene again and it gets shot down just as quickly, it's a signal to traders that Japan's intervention strategy is losing its effectiveness. As such, the threat of intervention itself is just as important a tool for Tokyo officials to make work at the moment.But the more USD/JPY gets pushed higher from here, the more it will test their limit and patience before acting. Will they decide to come in later this week when the US is on holiday? Hmm. This article was written by Justin Low at investinglive.com.