Mish quotes Bloomberg (the link is broken)

The 400 billion yen $5.2 billion sale drew bids valued at 2.03 times the amount on offer, the weakest since the Ministry of Finance began selling the securities in 2007.

The yield on the 2.2 percent bond maturing in March 2051 jumped 15 basis points to 2.335 percent as of 5:07 p.m. in Tokyo at Japan Bond Trading Co., the nation’s largest interdealer debt broker.

Japan’s Ministry of Finance said that every 1 percentage- point increase in 10-year yields above 2 percent would add 1 trillion yen in debt-servicing costs to a projection of 22.9 trillion yen for the fiscal year starting April 2012. The nation’s total debt may reach 219 percent of gross domestic product next year, according to the Organization for Economic Cooperation and Development.

via Mish’s Global Economic Trend Analysis: Worst Demand on Record for Japanese 40-Year Bonds; Can Japan Service its Debt? How?.

Mish comments:

nearly all of that demand is internal.

Internal demand is a double-edged sword. Right now it is still sufficient. However, when (not if), Japan ever needs foreign buyers for its bond market, rates will not be 2.3% on 40-year bonds.

Here is the key: If Japan does not maintain a trade surplus covering both interest on its national debt and bond redemptions, all hell will break loose. This gives rise to the question as to how long Japan’s vaunted export machine can remain intact. I do not have the answer to that question, but China and the rest of Asia are nibbling away bits and pieces now. The tsunami sure did not help.

It is mathematically impossible for every country to maintain a trade surplus, yet every country wants to do just that.