Chrysler and General Motors breathed sighs of relief Friday after President George W. Bush decided to extend up to $17.4 billion in loans to the stricken automakers.

It's about time. As Mr. Bush noted, a collapse of the companies would have seriously worsened the nation's economic crisis. But if anyone thinks this solves the industry's problems, they are mistaken.

GM and Chrysler face the roughest three months in their history as they struggle to come up with a plan to make themselves viable and competitive -- without further taxpayer subsidy. If they fail at that, the government will call in the loans and pull the plug.

Persuading Congress and the incoming Obama administration that they are on the right road won't be easy. Though the credit crunch brought Chrysler and GM to their knees and crippled Ford, it merely accelerated a problem that has been building for a long time. The companies have been losing market share, their business model is broken and they've negotiated unrealistic contracts.

Unless they and their unions get serious about restructuring and reinventing themselves, they will be doomed.

GM needs to realize that fooling around with a few nameplates and slowly reducing Pontiac won't do the job. Chrysler has to find itself a merger partner, and soon. The unions need to know that suspending the infamous "jobs bank" won't be enough either.

Even in a best-case scenario, many of the 240,000 people working for the Big Three today won't be there in a year. In Pennsylvania, says the Economic Policy Institute, up to 120,000 auto-related jobs could be lost if the three companies went bankrupt.

Though it took him too long to make up his mind, President Bush deserves credit. His decision to grant the loans went against his own beliefs, but he recognized that the economic welfare of the nation was threatened.

Now it is Detroit's turn. Perhaps a great statesman put it best. Years ago, when America and Great Britain won a small victory early in World War II, Winston Churchill said, "This is not the end. This is not even the beginning of the end. But it is, perhaps, the end of the beginning."

Chrysler, General Motors and the UAW have until March 31 to prove they have what it takes to live to fight another day.