WASHINGTON, Reuters The success of Japan and South Korea at inserting language voicing concern over their currencies in a joint statement with the U.S. this week underscores the political heat they face from stiff inflation that is being aggravated by weak exchange rates.

The matter is all the more urgent with Middle East tensions threatening to push up oil prices and accelerate cost pressures that have already exacted a domestic political toll on both governments. For the U.S., the statement was a small price to pay to placate a pair of allies it needs to keep on board with a more strategic goal of containing China.

In the first trilateral finance dialogue since last year39;s historic threeway leaders summit at Camp David, the U.S., Japan and South Korea agreed on Wednesday to consult closely on currency markets, acknowledging serious concerns from Tokyo and Seoul over the slumping Japanese yen and South Korean won.

The U.S. dollar has appreciated broadly this year on prospects for a delay in the U.S. Federal Reserve39;s shift to interest rate cuts, but the yen and won have weakened far more against the greenback than most other currencies. On the heels of the statement, the yen rebounded as markets braced for the risk of intervention, with some traders flagging the possibility of coordinated action along the lines of the 1985 Plaza Accord. The won stabilized as well.

The fact such strong language was used in the statement is a huge accomplishment for Japan and…