Paul Hiltemann had already noticed a darkening mood in the Netherlands. He runs an agency for people wanting to emigrate, and his client list had surged.
But he was still taken aback in November when a Dutch filmmaker was shot and his throat slit on an Amsterdam street.
In the weeks that followed, Hiltemann was inundated by e-mail messages and telephone calls. "There was a big panic," he said, "a flood of people saying they wanted to leave the country."
Leave this stable and prosperous corner of Europe? Leave this land with its generous social benefits and ample salaries, a place of fine schools, museums, sports grounds and bicycle paths, all set in a lively democracy?
The answer, increasingly, is yes. This small nation is a magnet for immigrants, but statistics suggest there is a quickening flight of the white middle class. Dutch people pulling up roots said they felt a general pessimism about their small and crowded country and about the social tensions that had grown along with the waves of newcomers, most of them Muslims.
"The Dutch are living in a kind of pressure cooker atmosphere," Hiltemann said.
There is more than the concern about the rising complications of absorbing newcomers, now one-tenth of the population, many of them from largely Muslim countries. Many Dutch also seem bewildered that their country, run for decades on a cozy, political consensus, now seems so tense and prickly and bent on confrontation. Those leaving have been mostly lured by English-speaking nations like Australia, New Zealand and Canada, where they say they hope to feel less constricted.
In interviews, emigrants rarely cited a fear of militant Islam as their main reason for packing their bags. But the killing of the filmmaker Theo van Gogh, a fierce critic of fundamentalist Muslims, seems to have been a catalyst.
"Our Web site got 13,000 hits in the weeks after the van Gogh killing," said Frans Buysse, who runs an agency that handles paperwork for departing Dutch. "That's four times the normal rate."
Van Gogh's killing is the only one the police have attributed to an Islamic militant, but since then they have reported finding death lists by local Islamic militants with the names of six prominent politicians. The effects still reverberate. In a recent opinion poll, 35 percent of the native Dutch questioned had negative views about Islam.
In 1999, nearly 30,000 native Dutch moved elsewhere, according to the Central Bureau of Statistics. For 2004, the provisional figure is close to 40,000.
"It's definitely been picking up in the past five years," said Cor Kooijmans, a demographer at the bureau.
Ruud Konings, an accountant, has just sold his comfortable home in the small town of Hilvarenbeek. In March, after a year's worth of paperwork, the family will leave for Australia. The couple said the main reason was their fear for the welfare and security of their two teenage children.
"When I grew up, this place was spontaneous and free, but my kids cannot safely cycle home at night," said Konings, 49. "My son just had his fifth bicycle stolen." At school, his children and their friends feel uneasy, he added. "They're afraid of being roughed up by the gangs of foreign kids."
Complaints include overcrowding, endless traffic jams, overregulation. Some cite a rise in antisocial behavior and a worrying new toughness and aggression both in political debates and on the streets.