Historical Pattern
Japan has repeatedly needed outside help to stabilize the yen
Asian Financial Crisis
Yen fell to 146/dollar amid Japan's banking crisis. US and Japan intervened jointly for the first time since 1995.
Great East Japan Earthquake
Yen spiked on repatriation bets after the disaster. G7 intervened jointly to cap the surge.
40-year yen weakness
Yen hit 163.7/dollar amid widening rate gaps and Middle East-driven oil costs. US joined Japan to buy yen, first time since 1998.