In the right hands, big turnarounds do happen.

Over the past months you've heard a lot about the country's least-able chief executives. The list of the overconfident and overpaid has been rehearsed so many times it's not worth bothering with the details. You know all about the folks who ran their companies into the ground.

Yet at the same time, over the last few years, the business world has witnessed a number of important and telling turnaround stories. Fiat is the one that's obviously most relevant now and the closest at hand. But you don't have to go abroad to find them.

In the United States, two that stand out are Hewlett-Packard (HPQ) and Boeing (BA). Certainly neither was on the brink of insolvency. But five years ago neither looked in any way promising. Hewlett-Packard had bulked up with a $25 billion deal to buy Compaq and was still getting clobbered in the market. Boeing was losing the race for new plane orders to a rival—the European Airbus—for the first time in history.

In a very short time, things changed. HP replaced Carly Fiorina, who had sold Hewlett Packard's board on the Compaq merger but who never succeeded in making it work, with an outsider, Mark Hurd, who did. Between 2004 and 2006, HP's profits quadrupled. Boeing grabbed back the clear lead in commercial aviation as Airbus' grand plans for the A380—the plane that seemed certain to eclipse the Boeing 747—nearly imploded.

Fiat, HP, and Boeing had very different approaches. Fiat's Marchionne proved to be a stellar negotiator, surprising everyone by cutting costs and making peace with the unions without closing down plants. HP's Hurd's approach was very different (and probably more painful): dramatic cuts in staff and costs.

At Boeing, Harry Stonecipher, then the chief executive, and Alan Mullaly, Boeing's commercial jets head—he's now Ford's CEO—proved to be exceptionally prescient strategists. They took an enormous gamble, betting that airlines would be more interested in a mid-size, superefficient plane, the 787, than a new jumbo jet that would compete with the A380.