JPY

If that's the case Ashraf, then it sounds like celebrity death match ... But the Chinese likely have a bigger toolkit to choose from than their counterparts and the market/history in their sails.

...meanwhile, Beijing keeps its own currency tightly controlled to benefit its exporters.

The yuan has risen less than 1 percent against the dollar since mid-June when Beijing said it would allow it to trade more freely after keeping it virtually unchanged for 18 months.

It is repeated all over that will help the export industry. I think the jap industry exported about the same quantities when USDJPY was 94 ( during the EUR crisis ) as they do now but they got more JPY and that was counter deflation. Japan exports machines autos electronics home appliances all these depned in demand on the state of US economy and this hasn't changed since. So the BoJ still attempts to fight deflation and that helps US treasury to sell more debt.
I am pretty confident it won't work. Especially the Boj tends at the end of Sept always to inject ample supply. The only winner so far is US treasury and with respect ot FOMC I think the timing of intervention was wrong.

Yes I keep on scratching...
Goldman analyst says the BOJ has Y35 trillion of intervention capacity.
That is about USD 400 bln . Geithner needs not worry about UST auctions meeting lukewarm demand, rather the treasury doesn't have enough treasuries to sell...