IN the narrative that has governed American commercial life for the last quarter-century, saving companies from their own mistakes was not supposed to be part of the government’s job description. Economic policy makers in the United States took swaggering pride in the cutthroat but lucrative form of capitalism that was supposedly indigenous to their frontier nation.

Through this uniquely American lens, saving businesses from collapse was the sort of thing that happened on other shores, where sentimental commitments to social welfare trumped sharp-edged competition. Weak-kneed European and Asian leaders were too frightened to endure the animal instincts of a real market, the story went. So they intervened time and again, using government largess to lift inefficient firms to safety, sparing jobs and limiting pain but keeping their economies from reaching full potential.

There have been recent interventions in America, of course  the taxpayer-backed bailout of Chrysler in 1979, and the savings and loan rescue of 1989. But the first happened under Jimmy Carter, a year before Americans embraced Ronald Reagan and his passion for unfettered markets. And the second was under George H. W. Bush, who did not share that passion.

So it made for a strange spectacle last weekend as the current Bush administration, which does cast itself in the Reagan mold, hastily prepared a bailout package to offer the government-sponsored mortgage companies, Fannie Mae and Freddie Mac. The reasoning behind this rescue effort  like the reasoning behind the government-induced takeover of Bear Stearns by J. P. Morgan Chase just a month before  sounded no different from that offered in defense of many a bailout in Japan and Europe:

The mortgage giants were too big to be allowed to fail.

Big indeed. Together, Fannie and Freddie own or guarantee nearly half of the nation’s $12 trillion worth of home mortgages. If they collapse, so may the whole system of finance for American housing, threatening a most unfortunate string of events: First, an already plummeting real estate market might crater. Then the banks that have sunk capital into American homes would slip deeper into trouble. And the virus might spread globally.