Over-reliance on the financial industry largely explains why Britain, which came into the crisis with relatively low public debt, has seen its budget deficit soar to 11 percent of G.D.P. — slightly worse than the U.S. deficit. And there’s no question that Britain will eventually need to balance its books with spending cuts and tax increases.

The operative word here should, however, be “eventually.” Fiscal austerity will depress the economy further unless it can be offset by a fall in interest rates. Right now, interest rates in Britain, as in America, are already very low, with little room to fall further. The sensible thing, then, is to devise a plan for putting the nation’s fiscal house in order, while waiting until a solid economic recovery is under way before wielding the ax.

But trendy fashion, almost by definition, isn’t sensible — and the British government seems determined to ignore the lessons of history…

The British government’s plan is bold, say the pundits — and so it is. But it boldly goes in exactly the wrong direction. It would cut government employment by 490,000 workers — the equivalent of almost three million layoffs in the United States — at a time when the private sector is in no position to provide alternative employment. It would slash spending at a time when private demand isn’t at all ready to take up the slack.