C. Rosser,
I don't think that there is a shortage of treasuries out there.
Selling treasuries doesn't do the Yen any good unless you then use the
proceeds to buy Yen. If treasury sales raise U.S. interest rates, the
spread between Japanese and American yields gets wider. I think the
Japanese were using the big sale to threaten the markets with their
immense reserves. I'm sure Washington approves of anything that keeps the
Yen higher (note recent earnings reports' citing for-ex losses), but I
don't think this is coordination.
peace