Reuters treats the yen’s violent swings as a market mystery, but the real story runs through the machinery of dollar-centered finance. Japan is a wealthy imperial-core creditor with enormous reserves and U.S. assets, yet its monetary choices remain constrained by U.S. rates, Treasury markets, imported energy, public debt, and capital flows. That dependence is reciprocal but unequal: Japanese instability can hurt Washington even as Tokyo adjusts inside a system it doesn’t command. And the costs travel downward. Workers win raises, then war-driven oil shocks, currency weakness, and inflation threaten to eat them away—turning monetary sovereignty into a class struggle over who pays.