Japan's top currency diplomat, Atsushi Mimura, warned on Thursday, 12 November 2026, that markets should not forget this summer's yen-buying intervention, as the yen again edged towards the key level of 160 per dollar. The dollar rose to 159.94 yen early on Thursday, its strongest in more than two months.

Mimura, Japan's vice finance minister for international affairs, was speaking in his first remarks on foreign exchange since late September. He said he believed recent currency moves had been excessively rapid, a phrase traders read as a signal that Tokyo is watching the market closely and is prepared to act.

What Mimura said

“It's still too early to forget what happened this summer,” Mimura said, referring to Japan's yen-buying interventions in late July through early August, including one conducted jointly with the United States. The reminder was deliberate: the summer operations showed that Tokyo is willing to step into the market, and to do so alongside Washington, when it judges the yen's fall to have gone too far.

The warning comes as the yen faces renewed pressure. The dollar was buoyed by growing expectations that the US Federal Reserve will raise interest rates, after hot US inflation data and hawkish remarks from policymakers. A stronger dollar and a weaker yen make Japanese imports more expensive, and the yen-based import price index jumped 24.8 percent in October from a year earlier, data showed on Thursday.

Why the yen is under pressure

Analysts at Mizuho Securities said the dollar was likely to keep rising against the yen, supported by the resilience of the US economy and persistently high inflation driven by heavy investment in artificial intelligence. That combination keeps US interest rates higher for longer, widening the gap with Japan and drawing money towards the dollar.

For Japan, the weak yen is a headache for policymakers. Import costs have surged, feeding into prices for energy, food and raw materials, and squeezing households and smaller businesses. The government of Prime Minister Sanae Takaichi is sensitive to the political cost of rising living costs, which adds to the pressure on the currency authorities to be seen to respond.

What could happen if the yen breaks 160

The 160 level is widely watched as a line in the sand. Mizuho Securities said in a report that if the dollar breaks above 160 and the weaker yen fuels inflation, increasing the risk of a fall in support for Takaichi's government, Tokyo could carry out unilateral intervention to support the currency.

Intervention is not a step Japan takes lightly. Buying yen to support it costs foreign reserves, and its effect can fade quickly if the underlying drivers, such as the gap between US and Japanese interest rates, do not change. The joint operation with the US in the summer showed, however, that Tokyo can act with force when it chooses, and Mimura's comments were designed to make traders think twice before testing the 160 level.

For now, the market is waiting. If the dollar pushes through 160, the question will be whether Mimura's warning was the last word before action, or simply an attempt to slow the yen's slide with words alone.

Sources: Reuters.