The yen has weakened back toward 160 per dollar after briefly strengthening to about 155 following the late-July U.S.-Japan intervention from levels above 163.8, highlighting how the underlying pressure on Japan's currency remains largely intact. Analysts and investors continue to focus on the wide interest-rate differential between the United States and Japan, cited here at 2.75 percentage points, as the main structural driver of yen weakness because it keeps capital flowing toward higher-yielding dollar assets. Jesper Koll of Monex Group said intervention cannot override the basic incentive for money to move to where returns are highest. Markets are now watching whether Japanese authorities step in again if the dollar rises above 160 yen, with attention also on the Federal Reserve's FIMA repo facility as a potential way for Japan to obtain dollars against its U.S. Treasury holdings to support intervention without outright bond sales. The latest account also adds that higher oil prices have increased pressure on the yen as momentum faded in talks on reopening the Strait of Hormuz. That is particularly important for Japan because it imports 90% of its crude oil from the Middle East. Park Sang-hyun of iM Securities said investors would still question how long any renewed intervention could remain effective, and argued that even a Bank of Japan rate increase in September could perversely weaken the yen if markets conclude the tightening cycle is already near its end. The won, which has tended to move with the yen, remained comparatively firm. South Korea's won-dollar rate stood at 1,415.7 in daytime trading on August 12, down 0.3 won from the previous session and 31 won lower than in late July.