The numbers, the projections, make health economists shudder.

The average per capita cost of health care in the United States is over $8,000 annually, double the amount spent in most European countries. The Congressional Budget Office projects that unless costs are brought under control in the next decade, the nation will be spending all of its tax revenues on health care, Social Security, interest on the debt and defense — but mostly health care.

“If we solve our health care spending, practically all of our fiscal problems go away,” said Victor Fuchs, emeritus professor of economics and health research and policy at Stanford University. And if we don’t? “Then almost anything else we do will not solve our fiscal problems.”

Dr. Fuchs, who has been called the dean of American health care economists, has spent five decades studying the health care problem. In his view, what is needed is the sort of major change that comes once in a decade, perhaps, or even just once in a generation.

But change, he believes, will not bubble up from within the health care system itself.

Here, edited and condensed for space, is a recent conversation with Dr. Fuchs about the nation’s health care costs.