Currency markets are on high alert for intervention from Japan’s central bank to weaken the yen, which jumped to a seven-month peak overnight after the Federal Reserve outlined aggressive steps to revive the U.S. economy.

Analysts say that any intervention to crimp yen strength, which is hurting exporters, is likely to have only a short-term impact and to really take the wind out of the sails of the strong yen, Japan needs to follow through with monetary easing steps of its own.