With a rare joint US-Japan market intervention weeks ago failing to rectify the weakness of the Japanese currency, Tokyo and Washington could be forced to launch another round of boosting efforts, with a deepening US Treasury rout expected to fuel the global yen carry trade, according to analysts. The yen has been on a sustained decline, falling to a 40-year low to trade above 163 per US dollar in late July. Though the US-Japan intervention briefly halted its slide, the currency has already...