DAVOS, Switzerland – For the first time in four years, hope filled the wintry air in the Swiss skiing village of Davos, where 1,000 of the world’s top business leaders opened an annual meeting Wednesday.

After a recession, the Sept. 11 terrorist attacks, corporate scandals and a war in Iraq, the chief executives are hoping the worst is behind the world’s economy.

Walter Kielholz, the chairman of the board of Credit Suisse Group, the Swiss bank, said he hoped to take away from the five-day event “a positive outlook so that we get out of this very depressing phase which we have (had) over the last three or four years in Davos.”

He added, though, that the optimism “stands on fairly fragile grounds.”

John Chambers, the president of Cisco Systems Inc., said he was looking for confirmation of his view that “the economy is absolutely headed the right way.” The meeting “gives you a forum to see what’s going on around the world from many different points of view.”

Participants – at least those who didn’t spring for the helicopter transfer from Zurich’s airport – slogged on roads through a heavy snowstorm to get to the World Economic Forum, an opportunity to wheel and deal and to take the economic and political pulse of the world.

The meeting also brings in 1,000 nonbusiness participants, ranging from academics to government leaders, including Vice President Dick Cheney.

While post-Sept.-11 security and the war in Iraq have weighed on recent conferences, the mood is cautiously upbeat this year. The grounds for optimism include the strong economic pickup in the United States, which should benefit other countries as well, and the capture of Saddam Hussein.

“I’m bullish about the U.S. economy, and because the U.S. economy is the key locomotive of the world, I am basically bullish about the world economy,” said Jacob Frenkel, the London-based chairman of Merrill Lynch International and a former governor of the Bank of Israel.

Not everyone sang the same tune. Stephen Roach, the chief economist at Morgan Stanley investment bank in New York, warned the business leaders that the U.S. economy is at risk because of high consumer debt and its failure to create many jobs in this recovery.

For now, the U.S. economy is relying on tax cuts and low interest rate-fueled home sales and mortgage refinancings. “I would put to you that today the main engine of the global economy, the U.S., is right now running on fumes,” Roach said.

Ultimately, the confidence of business leaders may determine whether the U.S. recovery falters. If businesses invest and hire, the recovery is likely to last.

Business leaders also are hoping that the corporate scandals are fading, though they said better practices in this area remained a hot topic. “This is something I will be particularly curious on, to see exactly where we are, what are the best ideas that we can use,” said Carlos Ghosn, the president of Japan’s Nissan Motor Co.