Most of the time, currency values move based on decentralized market forces — but in September 1985, five of the world's major economies deliberately intervened to reshape one. Representatives from the United States, Japan, West Germany, France, and the United Kingdom met at New York's Plaza Hotel and agreed to coordinate action to depreciate the US dollar, which had become sharply overvalued through the early 1980s and was hurting American export competitiveness while widening the US trade deficit to levels policymakers considered unsustainable.
The agreement, now known as the Plaza Accord, involved central banks coordinating currency interventions — directly buying and selling currencies in the open market to push the dollar lower against the yen and Deutsche mark in a deliberate, publicly announced fashion rather than through quiet, unilateral action. It worked dramatically: the dollar fell roughly 50% against the yen over the following two years, one of the largest coordinated currency moves in modern history, and a rare example of major economies successfully aligning monetary policy goals in public view.
The Plaza Accord is frequently cited in discussions of Japan's later economic history, as the sharply stronger yen contributed to conditions that some economists link to Japan's asset price bubble in the late 1980s and its subsequent prolonged economic stagnation through the 1990s, sometimes called Japan's "Lost Decade."
For forex traders and students of the market, the episode remains a rare, clear example of coordinated multilateral intervention actually working as intended — a contrast to many other historical intervention attempts, where markets often overwhelmed the actions of a single central bank instead, rendering the intervention largely ineffective or short-lived.
The Plaza Accord also set a template that policymakers have referenced ever since, even when they haven't replicated it. Later attempts at coordinated intervention, including the 1987 Louvre Accord aimed at stabilizing the dollar after its Plaza-driven decline, drew directly on the precedent — though none have matched the scale or clarity of the original agreement's stated goals and outcomes.
