Japan Signals It Would Join Washington in Another Yen Intervention
- Japan and U.S. authorities coordinated currency intervention last weekend to curb historic yen depreciation.
- Japan will use U.S. dollar-raising mechanisms to secure sufficient funds for yen purchases.
- Both sides are monitoring market conditions and may conduct further coordinated interventions.
- This move highlights Japan's determination and capability to stabilize the yen.
For Taiwanese readers, the past fortnight cut two ways. The dollar touched nearly 164 yen in late July — a level unseen in about four decades — before Tokyo and Washington bought yen together on 31 July and dragged the rate back to around 155. Travellers just lost their cheapest entry point; holders of yen deposits and Japanese property just recovered some paper value.
Private brokers estimate the operation exceeded 4 trillion yen. It moved the rate more than five yen in one night, and crucially the level has held. Japan says it will tap US dollar-funding arrangements to keep ammunition ready — logistics, not a one-off gesture.
Precedent is thin. The last joint US-Japan intervention came after the 2011 earthquake, fifteen years ago. Two treasuries standing against the market prices very differently from one. Yet Treasury Secretary Bessent called the move "symbolic," which caps how far Washington will go.
Three paths follow. The BOJ hikes in September, the gap narrows, and the rate returns to 145-150. Or rates stay put — the likeliest case, since the BOJ held on 31 July — and 160 gets retested. Or Washington steps back and Tokyo acts alone, buying less room for the same money.
The pivot sits with the BOJ, not the Ministry of Finance. Watch three things: the September policy meeting, the month-end intervention tally, and whether a joint statement names an actual threshold.
One cost sits out of sight: Japan buys yen with dollars held in its foreign-exchange special account, and most of that is US Treasuries. Selling them to fund intervention risks pushing US long-term yields up — which is why Tokyo stressed it will draw on US dollar-funding arrangements instead. Helping Japan also protects Washington's own bond market.