jimsaftcolumn– James Saft is a Reuters columnist. The opinions expressed are his own –

Efforts to reflate the economies of the U.S. and Britain are running into one potentially major problem; the bond market.

Appetite for government debt in recent sales has been very poor, raising the cost to the two governments of borrowing and blunting their efforts to bring down market interest rates by buying back their debt.

This is a big risk for British and U.S. efforts to rescue their economies, and could be yet another self reinforcing downward force if holders of government debt get the frights.

Both countries are running hugely expansionary fiscal stimulus programs that will need to be paid for by gargantuan sales of government debt. At the same time both have such low official interest rates, 0 to 25 basis points for the U.S. and