The Netherlands, visitors have long observed, seems the very embodiment of tolerance. To stroll along Amsterdam's central canals is to see cops bicycling through a haze of marijuana smoke while heroin addicts, drunk British tourists, pimps and prostitutes commingle in the alleys. Historically, the story goes, the Netherlands' legendary tolerance made it one of the world's greatest commercial powers -- and one of the few to accommodate Catholics, Protestants, Jews and a host of foreigners with little of the friction found elsewhere in 17th- and 18th-century Europe.